function validate_required(field,alerttxt)
{
with (field)
{
if (value==null||value==""||value==" ")
  {alert(alerttxt);return false}
else {return true}
}
}

function validate_form(thisform)
{
	with (thisform)
	{
		if (validate_required(productColour,"Please select a colour for the product")==false)
		  {productColour.focus();return false}
	
		if (validate_required(productSize,"Please select a size for the product")==false)
		  {productSize.focus();return false}
	}
}