function checkTotal(form) {
	var sum = 0;
	var units = 0;
	var productOptions = form.productpr.value.split(":");
	var optionName = "";
	var productName = productOptions[0].substring(0,productOptions[0].lastIndexOf("~")+1);
	for (i=0;i<form.checks.length;i++) {
	  if (form.checks[i].checked) {
		var opts = form.checks[i].value.split(":");
		var separator = (optionName == "" ? "" : ",");
		optionName = optionName+separator+opts[0];
		units = units + parseInt(opts[2]);
		sum = sum + parseInt(opts[1]);
	  }
	}
	form.productpr.value = productName+" "+optionName+":"+sum+":"+units;
}