function trimString (str) {
  str = this != window? this : str;
  return str.replace(/^\s+/g, '').replace(/\s+$/g, '');
}

function validateCart(fn,num,reqNumStart) {
	var validate = true;
	
	var formObject = document.forms[fn];
		
	for (i = num; i >= 0;  i--) {
		
		var fieldValue = formObject.elements[i].value;
		fieldValue = trimString(fieldValue);
		formObject.elements[i].value = fieldValue;
		
		var idx = reqNumStart + i;
		
		var warning = "required_" + idx;
		
		if (formObject.elements[i].value == 0) {
			formObject.elements[i].focus();
			formObject.elements[i].style.backgroundColor = "#FFCCCC";
			document.getElementById(warning).style.display = "inline";
			validate = false;
		}
		
		else {
			formObject.elements[i].style.backgroundColor = "#FFFFFF";
			document.getElementById(warning).style.display = "none";
		}
	}
	
	if (validate == true) {
		formObject.submit();
	}
}


function validateField (formElement,idx) {
	var warning = "required_" + idx;
	
	if (formElement.value != 0) {
		formElement.style.backgroundColor = "#FFFFFF";
		document.getElementById(warning).style.display = "none";
	}
	
}