//check that all fields with classname 'required' are filled in
function validateCheckout(){
var elems=document.getElementsByTagName('input'); 
for(var i=0;i<elems.length;i++){
	if((elems[i].className=='required')&&(elems[i].value=="")){
		alert("Please fill in all required fields");
		return false;
	}
}
return true;
}


function isNumeric(id){
	var ValidChars = "0123456789";
   	var IsNumber=true;
   	var Char;
	sText = document.getElementById(id).value;
	if((sText=="") || (sText=="0")){
		alert("Please set a quantity");
		return false;
	}
	for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
			 alert("Numeric values only please.");
         	return false;
         }
      }
   return IsNumber;
 }