function validate_form() {
var checkbox_choices = 0;
for (counter = 0; counter < document.compareselform.ProdComp.length; counter++)
{
	if (document.compareselform.ProdComp[counter].checked)
	{ checkbox_choices = checkbox_choices + 1; }
}
if (checkbox_choices < 2)
{
	alert("Please select at least two products to compare");
	return false;
}
else {
	return true;
}
}

function checkall(field,list) {
for (i = 0; i < list.length; i++)
{
	list[i].checked = field.checked;
}
}