diff --git a/Client/Client.cpp b/Client/Client.cpp
index f939aab..2a3e0f7 100644
--- a/Client/Client.cpp
+++ b/Client/Client.cpp
@@ -105,3 +105,14 @@ void Client::onSendPrivateMessage(QString receiver, QString message, QString sen
 	std::string package = packaging.createPivatePackage(receiver.toStdString(), message.toStdString(), sender.toStdString());
 	sendPackage(QString::fromStdString(package));
 }
+
+void Client::onSendFile(QByteArray blob, int fileSize, QString receiver, QString sender) {
+	// send over the file_size package
+	std::string package = packaging.createFileSizePackage(fileSize);
+	sendPackage(QString::fromStdString(package));
+
+	tcpSocket->waitForBytesWritten();
+	tcpSocket->flush();
+	package = blob.toStdString();
+	sendPackage(QString::fromStdString(package));
+}
diff --git a/Client/Client.h b/Client/Client.h
index c36496f..7b89e0b 100644
--- a/Client/Client.h
+++ b/Client/Client.h
@@ -7,6 +7,7 @@
 #include <QIODevice>
 #include <QTcpSocket>
 #include <QDataStream>
+#include <QThread>
 
 #include "../util/Packaging.h"
 
@@ -47,6 +48,7 @@ public slots:
 	void onLogoutRequest();
 	void onGlobalPackage(QString message);
 	void onSendPrivateMessage(QString receiver, QString message, QString sender);
+	void onSendFile(QByteArray blob, int fileSize, QString receiver, QString sender);
 };
 
 #endif // CLIENT_H
diff --git a/Client/LoginDialog.cpp b/Client/LoginDialog.cpp
index b295897..3445507 100644
--- a/Client/LoginDialog.cpp
+++ b/Client/LoginDialog.cpp
@@ -1,5 +1,5 @@
 #include "LoginDialog.h"
-#include "ui_logindialog.h"
+#include "ui_LoginDialog.h"
 
 #include <QDebug>
 
diff --git a/Client/LoginDialog.ui b/Client/LoginDialog.ui
index 738a64a..d09148a 100644
--- a/Client/LoginDialog.ui
+++ b/Client/LoginDialog.ui
@@ -9,8 +9,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>300</width>
-    <height>210</height>
+    <width>250</width>
+    <height>197</height>
    </rect>
   </property>
   <property name="acceptDrops">
diff --git a/Client/MainWindow.cpp b/Client/MainWindow.cpp
index 4e873d2..e02d149 100644
--- a/Client/MainWindow.cpp
+++ b/Client/MainWindow.cpp
@@ -1,5 +1,5 @@
 #include "MainWindow.h"
-#include "ui_mainwindow.h"
+#include "ui_MainWindow.h"
 
 MainWindow::MainWindow(QWidget* parent) : QMainWindow(parent), ui(new Ui::MainWindow) {
 	ui->setupUi(this);
@@ -26,6 +26,7 @@ void MainWindow::onSignIn(QString username, QString password, QString serverAddr
 	this->password = password;
 	this->serverAddr = serverAddr;
 	this->port = port;
+	this->setWindowTitle(username);
 	initClient();
 }
 
diff --git a/Client/PrivateMessageDialog.cpp b/Client/PrivateMessageDialog.cpp
index 4211c63..23ce876 100644
--- a/Client/PrivateMessageDialog.cpp
+++ b/Client/PrivateMessageDialog.cpp
@@ -9,6 +9,9 @@ PrivateMessageDialog::PrivateMessageDialog(QWidget* parent, Client* client, QStr
 	connect(client, &Client::receivedPrivateMessage, this, &PrivateMessageDialog::onReceivedPrivateMessage);
 	connect(ui->btnSendMessage, &QPushButton::clicked, this, &PrivateMessageDialog::onSendMessageButtonClicked);
 	connect(this, &PrivateMessageDialog::sendPrivateMessage, client, &Client::onSendPrivateMessage);
+
+	connect(ui->btnSendFile, &QPushButton::clicked, this, &PrivateMessageDialog::onSendFile);
+	connect(this, &PrivateMessageDialog::sendFile, client, &Client::onSendFile);
 }
 
 PrivateMessageDialog::~PrivateMessageDialog() {
@@ -30,3 +33,21 @@ void PrivateMessageDialog::onSendMessageButtonClicked() {
 	QString output = sender + ": " + message;
 	ui->editRecvMessage->append(output);
 }
+
+void PrivateMessageDialog::onSendFile() {
+	QString fileName = QFileDialog::getOpenFileName(this, tr("Open file"), "/home",
+													tr("All files (*)"));
+	QFile file(fileName);
+	if (!file.open(QIODevice::ReadOnly)) {
+		QMessageBox::information(this, "File open error",
+								 tr("There was a problem with opening the file!"));
+		return;
+	}
+
+	QByteArray blob = file.readAll();
+	int fileSize = blob.size();
+	QString receiver = chatPartner;
+	QString sender = client->getUsername();
+
+	emit sendFile(blob, fileSize, receiver, sender);
+}
diff --git a/Client/PrivateMessageDialog.h b/Client/PrivateMessageDialog.h
index c52aa24..cbe254c 100644
--- a/Client/PrivateMessageDialog.h
+++ b/Client/PrivateMessageDialog.h
@@ -2,6 +2,10 @@
 #define PRIVATEMESSAGEDIALOG_HPP
 
 #include <QDialog>
+#include <QFileDialog>
+#include <QFile>
+#include <QByteArray>
+#include <QMessageBox>
 
 #include "Client.h"
 
@@ -27,10 +31,12 @@ class PrivateMessageDialog : public QDialog {
 signals:
 	void closeDialog(QString username);
 	void sendPrivateMessage(QString receiver, QString message, QString sender);
+	void sendFile(QByteArray blob, int fileSize, QString receiver, QString sender);
 
 public slots:
 	void onReceivedPrivateMessage(QString receiver, QString message, QString sender);
 	void onSendMessageButtonClicked();
+	void onSendFile();
 };
 
 #endif // PRIVATEMESSAGEDIALOG_HPP
diff --git a/Client/PrivateMessageDialog.ui b/Client/PrivateMessageDialog.ui
index 5d0f96b..ba672d5 100644
--- a/Client/PrivateMessageDialog.ui
+++ b/Client/PrivateMessageDialog.ui
@@ -6,8 +6,8 @@
    <rect>
     <x>0</x>
     <y>0</y>
-    <width>241</width>
-    <height>308</height>
+    <width>282</width>
+    <height>334</height>
    </rect>
   </property>
   <property name="windowTitle">
@@ -15,8 +15,8 @@
   </property>
   <layout class="QGridLayout" name="gridLayout_2">
    <item row="0" column="0">
-    <layout class="QGridLayout" name="gridLayout">
-     <item row="0" column="0" colspan="3">
+    <layout class="QGridLayout" name="gridLayout" rowstretch="0,1,0,0">
+     <item row="0" column="0" colspan="4">
       <widget class="QTextEdit" name="editRecvMessage">
        <property name="frameShape">
         <enum>QFrame::Panel</enum>
@@ -29,7 +29,7 @@
        </property>
       </widget>
      </item>
-     <item row="1" column="0" colspan="3">
+     <item row="1" column="0" colspan="4">
       <widget class="QTextEdit" name="editSendMessage">
        <property name="frameShape">
         <enum>QFrame::Panel</enum>
@@ -76,7 +76,7 @@ background-color: rgb(85, 255, 127);</string>
        </property>
       </widget>
      </item>
-     <item row="2" column="2">
+     <item row="2" column="3">
       <spacer name="horizontalSpacer_2">
        <property name="orientation">
         <enum>Qt::Horizontal</enum>
@@ -89,6 +89,17 @@ background-color: rgb(85, 255, 127);</string>
        </property>
       </spacer>
      </item>
+     <item row="2" column="2">
+      <widget class="QPushButton" name="btnSendFile">
+       <property name="styleSheet">
+        <string notr="true">
+background-color: rgb(85, 255, 127);</string>
+       </property>
+       <property name="text">
+        <string>Attach file</string>
+       </property>
+      </widget>
+     </item>
     </layout>
    </item>
   </layout>
diff --git a/Server/ClientThread.cpp b/Server/ClientThread.cpp
index 220a423..a9e578a 100644
--- a/Server/ClientThread.cpp
+++ b/Server/ClientThread.cpp
@@ -52,9 +52,12 @@ void* ClientThread::run() {
         } else if (request.compare("private_package") == 0) {
             std::cout << "request: " << "private_package" << "\n";
             onPrivateMessageRequest(package);
+        } else if (request.compare("file_size_package") == 0) {
+            std::cout << "request: " << "file transfer" << "\n";
+            onFileTransfer(package);
         }
         
-        std::this_thread::sleep_for(std::chrono::milliseconds(5000));
+        //std::this_thread::sleep_for(std::chrono::milliseconds(5000));
     }
 }
 
@@ -145,6 +148,20 @@ void ClientThread::onPrivateMessageRequest(const std::string& package) {
     sendPackageToTarget(package, receiver);
 }
 
+void ClientThread::onFileTransfer(const std::string& package) {
+    packaging.parsePackage(package);
+    int fileSize = stoi(packaging.getMessage());
+    std::cout << "file size: " << fileSize << "\n";
+    
+    std::this_thread::sleep_for(std::chrono::milliseconds(1000));
+    std::string readPackage = readFilePackage(fileSize);
+    //std::cout << readPackage;
+    std::ofstream file;
+    file.open("../output.txt", std::ios::out);
+    file << readPackage;
+    file.close();
+}
+
 void ClientThread::onLogoutRequest() {
     std::cout << "Disconnecting user..\n";
     // TODO: remove the disconnected user from the online user's list
@@ -157,13 +174,32 @@ void ClientThread::onLogoutRequest() {
 
 std::string ClientThread::readPackage() {
     int buffSize = sizeof(messageBuff);
-    char msgBuff[1024];
 
-    int res = recv(acceptSocket, msgBuff, buffSize, 0);
-    if (res != 0) {
+    int res = recv(acceptSocket, messageBuff, buffSize, 0);
+    if (res > 0) {
         std::cout << " bytes: " << res << "\n";
     }
-    if (res < 0) {
+    else if (res == 0) {
+        tcpserver->removeClient(user.getUsername());
+        pthread_exit(NULL);
+    }
+    else {
+        errorMsg = "error when receiving the message from the client!\n";
+        error(errorMsg.c_str());
+    }
+    messageBuff[res] = '\0';
+    return messageBuff;
+}
+
+std::string ClientThread::readFilePackage(int fileSize) {
+    int buffSize = sizeof(messageBuff);
+    char msgBuff[fileSize];
+    
+    int res = recv(acceptSocket, msgBuff, fileSize, 0);
+    if (res > 0) {
+        std::cout << "\n file bytes read: " << res << "\n";
+    }
+    else {
         errorMsg = "error when receiving the message from the client!\n";
         error(errorMsg.c_str());
     }
diff --git a/Server/ClientThread.h b/Server/ClientThread.h
index f82889e..4f27593 100644
--- a/Server/ClientThread.h
+++ b/Server/ClientThread.h
@@ -26,6 +26,8 @@
 #include <list>
 #include <vector>
 #include <algorithm>
+#include <fstream>
+#include <iostream>
 
 #include "../util/Packaging.h"
 #include "MyThread.h"
@@ -46,6 +48,7 @@ class ClientThread : public MyThread {
     void onLogoutRequest();
     void onGlobalMessageRequest(const std::string& package);
     void onPrivateMessageRequest(const std::string& package);
+    void onFileTransfer(const std::string& package);
     
     bool logoutRequest = false;
     
@@ -57,13 +60,16 @@ class ClientThread : public MyThread {
     
 private:
     int acceptSocket;
-    char messageBuff[1024];
+    char messageBuff[2048];
     
     /** basic information about a user */
     User user;
     void sendPackage(const std::string& package);
     /** reads the incoming package from the user */
     std::string readPackage();
+    /** reads a file package which comes right after the file's size package and saves into an output file */
+    std::string readFilePackage(int fileSize);
+    
     /** sends the package to every online user*/
     void sendPackageToAll(const std::string& package);
     void sendPackageToTarget(const std::string& package, const std::string& target);
diff --git a/Server/TCPServer.cpp b/Server/TCPServer.cpp
index ec6291d..439aabf 100644
--- a/Server/TCPServer.cpp
+++ b/Server/TCPServer.cpp
@@ -75,9 +75,19 @@ void TCPServer::startServer() {
     }
 }
 
-void TCPServer::removeClient(ClientThread& clientThread) {
-    //std::unique_ptr<ClientThread> clientPtr = static_cast<std::unique_ptr<ClientThread>>(&clientThread);
-    //usersPtr->remove(clientPtr);
+// TODO: remove client
+void TCPServer::removeClient(const std::string& username) {
+   /* std::cout << "nr of users: " << usersPtr->size() << "\n";
+    auto list = usersPtr.get();
+    std::list<std::unique_ptr<ClientThread>>::const_iterator iterator;
+    for (iterator = list->begin(); iterator != list->end(); ++iterator) {
+        std::string tmp = (**iterator).getUsername();
+        if (tmp.compare(username) == 0) {
+            break;
+        }
+    }
+    usersPtr->erase(iterator);
+    std::cout << "nr of users after delete: " << usersPtr->size() << "\n"; */
 }
 
 std::vector<std::string> TCPServer::getOnlineUsers() {
diff --git a/Server/TCPServer.h b/Server/TCPServer.h
index dfcd457..a2f4ff7 100644
--- a/Server/TCPServer.h
+++ b/Server/TCPServer.h
@@ -28,7 +28,7 @@ class TCPServer {
     virtual ~TCPServer();
     
     void startServer();
-    void removeClient(ClientThread& clientThread);
+    void removeClient(const std::string& username);
     std::vector<std::string> getOnlineUsers();
     
     void lockMutex() { pthread_mutex_lock(&mutex); }
diff --git a/util/Packaging.cpp b/util/Packaging.cpp
index 463d083..3d23e52 100644
--- a/util/Packaging.cpp
+++ b/util/Packaging.cpp
@@ -66,16 +66,26 @@ std::string Packaging::createOnlineUsersPackage(const std::vector<std::string>&
     // inserts the elements into the "joinedFields" stream, with the "," delimiter 
     std::copy(onlineUsers.begin(), onlineUsers.end(), std::ostream_iterator<std::string>(joinedFields, ","));
     std::string usersList = joinedFields.str();
-    // unnecessary delimiter on the end of the string
-    //usersList[usersList.length() - 1] = '\0';
-    /*std::string usersList;
-    usersList.assign(tmpStr, 0, tmpStr.length() - 1);*/
     this->receiver = "list_users";
     this->message = usersList;
     this->sender = "server";
     return constructPackage();
 }
 
+std::string Packaging::createFileSizePackage(int fileSize) {
+	this->receiver = "file_size";
+	this->message = std::to_string(fileSize);
+	this->sender = sender;
+	return constructPackage();
+}
+
+std::string Packaging::createFilePackage(const std::string& blob, const std::string& receiver, const std::string& sender) {
+	this->receiver = receiver;
+	this->message = blob;
+	this->sender = sender;
+	return constructPackage();
+}
+
 std::string Packaging::constructPackage() {
     std::string pckg = receiver + glue + glue + message + glue + sender + glue;
     size_t len = pckg.length();
@@ -127,6 +137,9 @@ std::string Packaging::identifyRequest(std::string package) {
         if (token.compare("list_users") == 0) {
             return "online_users_package";
         }
+		if (token.compare("file_size") == 0) {
+			return "file_size_package";
+		}
         // erase token + glue
         package.erase(0, pos + 1);
     }
diff --git a/util/Packaging.h b/util/Packaging.h
index 25206a2..919d55b 100644
--- a/util/Packaging.h
+++ b/util/Packaging.h
@@ -33,6 +33,7 @@
  *		- disconnect: message = "disconnect"
  *		- global: receiver = "global"
  *		- list_users: receiver = "list_users"
+ *		- file_size: receiver = "file_size"
 */
 class Packaging {
 public:
@@ -53,6 +54,10 @@ class Packaging {
     std::string createPivatePackage(const std::string& receiver, const std::string& message, const std::string& sender);
     /** package used to send the online user's list to a user */
     std::string createOnlineUsersPackage(const std::vector<std::string>& onlineUsers);
+	/** package used to signal the incoming file's size */
+	std::string createFileSizePackage(int fileSize);
+	/** package used to send a binary stream */
+	std::string createFilePackage(const std::string& blob, const std::string& receiver, const std::string& sender);
 
     void parsePackage(std::string package);