diff --git a/History.txt b/History.txt
index 76c12f8..2e9b1b8 100644
--- a/History.txt
+++ b/History.txt
@@ -1,3 +1,8 @@
+== 0.7.3 2009-03-21
+
+* New assertions: assertNotHasClass(element, class)
+* Fixed algorithm for assertHasClass
+
 == 0.7.2 2008-10-08
 
 * AJAX callback from IE6 working [choan]
diff --git a/Rakefile b/Rakefile
index 9968899..9a702fe 100644
--- a/Rakefile
+++ b/Rakefile
@@ -12,7 +12,7 @@ require 'rake/packagetask'
 
 $:.unshift File.dirname(__FILE__) + "/lib"
 
-APP_VERSION  = '0.7.2'
+APP_VERSION  = '0.7.3'
 APP_NAME     = 'jsunittest'
 RUBYFORGE_PROJECT = 'drnicjavascript'
 APP_FILE_NAME= "#{APP_NAME}.js"
diff --git a/src/assertions.js b/src/assertions.js
index f30b6cf..a5e33f4 100644
--- a/src/assertions.js
+++ b/src/assertions.js
@@ -146,8 +146,21 @@ JsUnitTest.Unit.Assertions = {
   assertHasClass: function(element, klass, message) {
     element = JsUnitTest.$(element);
     message = this.buildMessage(message || 'assertHasClass', '? doesn\'t have class <?>.', element, klass);
-    this.assertBlock(message, function() { 
-      return !!element.className.match(new RegExp(klass))
+    this.assertBlock(message, function() {
+      var elementClassName = element.className;
+      return (elementClassName.length > 0 && (elementClassName == klass ||
+        new RegExp("(^|\\s)" + klass + "(\\s|$)").test(elementClassName)));
+      // return !!element.className.match(new RegExp(klass))
+    });
+  },
+  
+  assertNotHasClass: function(element, klass, message) {
+    element = JsUnitTest.$(element);
+    message = this.buildMessage(message || 'assertNotHasClass', '? does have class <?>.', element, klass);
+    this.assertBlock(message, function() {
+      var elementClassName = element.className;
+      return !(elementClassName.length > 0 && (elementClassName == klass ||
+        new RegExp("(^|\\s)" + klass + "(\\s|$)").test(elementClassName)));
     });
   },
   
diff --git a/test/unit/assertions_test.html b/test/unit/assertions_test.html
index 4a53c61..6bcef00 100644
--- a/test/unit/assertions_test.html
+++ b/test/unit/assertions_test.html
@@ -165,10 +165,15 @@ <h1>JavaScript unit test file</h1>
     testHasClass: function() { with(this) {
       // <div id="test_1" class="a bbbbbbbbbbbb cccccccccc dddd"> </div>
       assertHasClass('test_1', 'a');
-      // info(document.getElementById('test_1').className);
       assertHasClass(document.getElementById('test_1'), 'dddd');
     }},
     
+    testNotHasClass: function() { with(this) {
+      // <div id="test_1" class="a bbbbbbbbbbbb cccccccccc dddd"> </div>
+      assertNotHasClass('test_1', 'abc');
+      assertNotHasClass(document.getElementById('test_1'), 'ddd');
+    }},
+    
     testAssertVisible: function() { with(this) {
       assertVisible('testcss1');
       assertNotVisible('testcss1_span');