function ChangeSize(osize) {
	thisform = osize.form;
	isize = osize.selectedIndex;
	ocolour = thisform.ProductColour;
	scolour = thisform.ProductColour.options[thisform.ProductColour.selectedIndex].value;
	
	ocolour.length = aitem[isize].length;
	for (i = 0; i < aitem[isize].length; ++i) {
		ocolour.options[i].text = aitem[isize][i]
		ocolour.options[i].value = aitem[isize][i]
		if (aitem[isize][i] == scolour)
			ocolour.selectedIndex = i
	}
}