function clear() {
	var aForm = document.plasticProdForm;
	for(i=0;i<aForm.comparableProductCheckBox.length;i++){
		if(aForm.comparableProductCheckBox[i].checked){
			aForm.comparableProductCheckBox[i].checked=false;
		}
	}
}

function compare(aForm) {
	var checkCount = 0;
	for(i=0;i<aForm.comparableProductCheckBox.length;i++){
		if(aForm.comparableProductCheckBox[i].checked){
			checkCount++;
		}
	}
	if(checkCount<2 || checkCount>4){
		alert("To compare products please tick 2 to 4 checkboxes and press compare");
		return false;
	}
	return true;
}