Javascript blur function in httpunit

It appears to me that the blur() javascript function isn't supported in httpunit since I get the error below in HTTPUnit 1.6.2 (latest) but not in HTTPUnit 1.6 since in version 1.6, CheckboxFormControl never actually called sendOnClickEvent() when checkbox is checked.

http://wp.netscape.com/eng/mozilla/3.0/handbook/javascript/ref_a-c.htm#62474 clearly shows that blur is a valid function for checkboxes...


 [junit] TypeError: blur is not a function. (httpunit; line 4)
 [junit]     at org.mozilla.javascript.NativeGlobal.constructError(NativeGlobal.java:597)
 [junit]     at org.mozilla.javascript.NativeGlobal.constructError(NativeGlobal.java(Inlined Compi
 [junit]     at org.mozilla.javascript.NativeGlobal.typeError1(NativeGlobal.java(Inlined Compiled
 [junit]     at org.mozilla.javascript.Interpreter.interpret(Interpreter.java(Compiled Code))
 [junit]     at org.mozilla.javascript.Interpreter.interpret(Interpreter.java(Compiled Code))
 [junit]     at org.mozilla.javascript.InterpretedFunction.call(InterpretedFunction.java:58)
 [junit]     at com.meterware.httpunit.javascript.JavaScript$JavaScriptEngine.performEvent(JavaScr
 [junit]     at com.meterware.httpunit.scripting.ScriptableDelegate.doEvent(ScriptableDelegate.jav
 [junit]     at com.meterware.httpunit.FormControl.sendOnClickEvent(FormControl.java:277)
 [junit]     at com.meterware.httpunit.CheckboxFormControl.setState(FormControl.java:706)
 [junit]     at com.meterware.httpunit.FormParameter.setValue(FormParameter.java:128)
 [junit]     at com.meterware.httpunit.WebForm.setCheckbox(WebForm.java:692)