Question About Using JavaScript Within WOCheckboxmatrix

Hi:
I have searched around the mailing lists and didn't see anything 
related to this subject.  I have a couple of WORadioButtons on my form, 
I want to be able to iterate through a WOCheckboxmatrix and 
disable/enable a set of checkboxes based on whether the radio buttons 
are checked, I have the following javascript function I wrote:

<SCRIPT LANGUAGE="JAVASCRIPT">
	function checkAllLanguages()
	{
		if (document.page1Form.LanguagesRadioButton[0].checked)
		{
			for (i=0;i<numCheckboxes;i++)
			{
				document.page1Form.languageCheckboxMatrix.item[i].disabled=true;
				document.page1Form.languageCheckboxMatrix.item[i].checked=true;
			}
		}
		else if (document.page1Form.LanguagesRadioButton[1].checked)
		{
			for (i=0;i<numCheckboxes;i++)
			{
				document.page1Form.languageCheckboxMatrix.item[i].disabled=false;
				document.page1Form.languageCheckboxMatrix.item[i].checked=false;
			}
		}		
	}
	</SCRIPT>


However when I check the radio buttons nothing happens, I was wondering 
if this is the correct way to access the elements inside a 
WOCheckboxmatrix.

Any help would be much appreciated, I am a newbie at using this element.

Thank you
Saikat