Cultivate Web Design Melbourne – Development Blog

window.addEvent('domready',function(){
	$$('input[name=Enquiry_type]').addEvent('change',function()
	{	var Enquiry_Categories = [['option 1','option 2','option 3'],['option 4','option 5','option 6'],['option 7','option 8','option 9']];

		$('Enquiry_Sub_Category').empty();

		for(i=0; i<Enquiry_Categories[$(this).get('value')].length; i++)
		{	var option = Enquiry_Categories[$(this).get('value')][i];
			$('Enquiry_Sub_Category').grab(new Element('option',{value: option, html: option}));
		}
	});
});

<!-- when this is selected-->
<select name="Enquiry_type">
<option value="0">select this for options 1,2,3</option>
<option value="1">select this for options 4,5,6</option>
<option value="2">select this for options 7,8,9</option>
</select>

<!--this will get populated-->
<select name="Enquiry_Sub_Category">
</select>

'option 1','option 1',