diff --git a/README.md b/README.md
index e908391..3799c61 100644
--- a/README.md
+++ b/README.md
@@ -27,9 +27,13 @@
 @implementation RegisterForm
 -(SurveyField *)firstname
 {
-    SurveyField *field  = [SurveyField fieldWithPlaceholder:@"First Name"];
-    field.isRequired    = NO;
-    field.label         = @"First Name";
+    SurveyField *field    = [SurveyField fieldWithPlaceholder:@"First Name"];
+    field.isRequired      = NO;
+    field.label           = @"First Name";
+    field.validationBlock = ^(id form, id field, id value) {
+        NSString *fieldValue = [(NSString *)value lowercaseString];
+        return [fieldValue isEqualToString:@"wess"];
+    };
     
     return field;
 }
diff --git a/Survey/Classes/SurveyField.h b/Survey/Classes/SurveyField.h
index 28b5042..87c0c12 100644
--- a/Survey/Classes/SurveyField.h
+++ b/Survey/Classes/SurveyField.h
@@ -8,17 +8,20 @@
 
 #import <Foundation/Foundation.h>
 
+typedef BOOL(^SurveyValidationBlock)(id form, id field, id value);
+
 @interface SurveyField : NSObject
-@property (copy, nonatomic)      NSString            *entityName;
-@property (copy, nonatomic)      NSString            *label;
-@property (copy, nonatomic)      NSString            *placeholder;
-@property (copy, nonatomic)      NSString            *value;
-@property (strong, nonatomic)    Class               fieldClass;
-@property (strong, nonatomic)    UITextField         *field;
-@property (strong, nonatomic)    NSRegularExpression *expression;
-@property (strong, nonatomic)    NSString            *errorMessage;
-@property (readwrite, nonatomic) BOOL                isRequired;
-@property (readwrite, nonatomic) BOOL                isSecure;
+@property (copy, nonatomic)      NSString               *entityName;
+@property (copy, nonatomic)      NSString               *label;
+@property (copy, nonatomic)      NSString               *placeholder;
+@property (copy, nonatomic)      NSString               *value;
+@property (strong, nonatomic)    UITextField            *field;
+@property (strong, nonatomic)    NSRegularExpression    *expression;
+@property (strong, nonatomic)    NSString               *errorMessage;
+@property (strong, nonatomic)    Class                  fieldClass;
+@property (strong, nonatomic)    SurveyValidationBlock  validationBlock;
+@property (readwrite, nonatomic) BOOL                   isRequired;
+@property (readwrite, nonatomic) BOOL                   isSecure;
 
 + (SurveyField *)fieldWithPlaceholder:(NSString *)placeholder;
 
diff --git a/Survey/Classes/SurveyField.m b/Survey/Classes/SurveyField.m
index 005ef48..b96166a 100644
--- a/Survey/Classes/SurveyField.m
+++ b/Survey/Classes/SurveyField.m
@@ -15,7 +15,8 @@ - (id)init
     self = [super init];
     if(self)
     {
-        _isRequired = NO;
+        _isRequired      = NO;
+        _validationBlock = NULL;
     }
     return self;
 }
diff --git a/Survey/Classes/SurveyForm.m b/Survey/Classes/SurveyForm.m
index 7884df1..9445e84 100644
--- a/Survey/Classes/SurveyForm.m
+++ b/Survey/Classes/SurveyForm.m
@@ -199,6 +199,18 @@ - (void)validateForm
             [mutableFieldErrors addObject:matchError];
         }
 
+        if(fieldObject.validationBlock != NULL)
+        {
+            BOOL isValid = fieldObject.validationBlock(self, fieldObject.field, value);
+            if(!isValid)
+            {
+                _fieldsAreValid = NO;
+            
+                NSString *matchError = (fieldObject.errorMessage)? fieldObject.errorMessage : @"Validation failed";
+                [mutableFieldErrors addObject:matchError];
+            }
+        }
+        
         [_fieldValues setObject:((value)? value : @"") forKey:fieldObject.entityName];
         
         if(mutableFieldErrors.count > 0)
diff --git a/SurveyExample/SurveyExample.xcodeproj/project.pbxproj b/SurveyExample/SurveyExample.xcodeproj/project.pbxproj
index 9641127..df76666 100644
--- a/SurveyExample/SurveyExample.xcodeproj/project.pbxproj
+++ b/SurveyExample/SurveyExample.xcodeproj/project.pbxproj
@@ -284,10 +284,7 @@
 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
 				GCC_PREFIX_HEADER = "SurveyExample/SurveyExample-Prefix.pch";
 				INFOPLIST_FILE = "SurveyExample/SurveyExample-Info.plist";
-				LIBRARY_SEARCH_PATHS = (
-					"$(inherited)",
-					"\"$(SRCROOT)/../../../Library/Developer/Xcode/DerivedData/Survey-efmxnwsndofvtxbkslugynnmuymv/Build/Products/Debug-iphoneos\"",
-				);
+				LIBRARY_SEARCH_PATHS = "$(inherited)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				WRAPPER_EXTENSION = app;
 			};
@@ -299,10 +296,7 @@
 				GCC_PRECOMPILE_PREFIX_HEADER = YES;
 				GCC_PREFIX_HEADER = "SurveyExample/SurveyExample-Prefix.pch";
 				INFOPLIST_FILE = "SurveyExample/SurveyExample-Info.plist";
-				LIBRARY_SEARCH_PATHS = (
-					"$(inherited)",
-					"\"$(SRCROOT)/../../../Library/Developer/Xcode/DerivedData/Survey-efmxnwsndofvtxbkslugynnmuymv/Build/Products/Debug-iphoneos\"",
-				);
+				LIBRARY_SEARCH_PATHS = "$(inherited)";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				WRAPPER_EXTENSION = app;
 			};
@@ -327,6 +321,7 @@
 				08C867F7162CE99200B98C14 /* Release */,
 			);
 			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
 		};
 /* End XCConfigurationList section */
 	};
diff --git a/SurveyExample/SurveyExample/WCRegisterForm.m b/SurveyExample/SurveyExample/WCRegisterForm.m
index c8b2009..4e0dd42 100644
--- a/SurveyExample/SurveyExample/WCRegisterForm.m
+++ b/SurveyExample/SurveyExample/WCRegisterForm.m
@@ -22,6 +22,12 @@ - (SurveyField *)lastname
     SurveyField *field  = [SurveyField fieldWithPlaceholder:@"Last Name"];
     field.isRequired    = YES;
     field.label         = @"Last Name";
+    field.validationBlock   = ^(id form, id field, id value) {
+        NSString *fieldValue = [(NSString *)value lowercaseString];
+        NSLog(@"FIELD VALUE: %@", fieldValue);
+
+        return [fieldValue isEqualToString:@"cope"];
+    };
     
     return field;
 }
diff --git a/hJHYq.png b/hJHYq.png
new file mode 100644
index 0000000..d0f1a5b
Binary files /dev/null and b/hJHYq.png differ