function inputCheck(){

	var msg = "Sorry...the following fields need completing:\n\n\n";
	var obj;
	var ret = true;

	if(document.mcddealers.int.value==""){
			msg += '- Reference No \n';
			obj = document.mcddealers.int;
			ret = false;
	}
	else if (IsNumeric(document.mcddealers.int.value) == false){
      msg += '- Reference No must be numeric \n';
      obj = document.mcddealers.int;
      ret = false;
  }
  
    if (!ret) {
   alert(msg);
  }
  return ret;
}

function IsNumeric(strString)
{
 //  check for valid numeric strings	
 var strValidChars = "0123456789 ";
 var strChar;
 var blnResult = true;

 if (strString.length == 0) return false;

 //  test strString consists of valid characters listed above
 for (i = 0; i < strString.length && blnResult == true; i++)
 {
  strChar = strString.charAt(i);
  if (strValidChars.indexOf(strChar) == -1)
  {
   blnResult = false;
  }
 }
 return blnResult;
}