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


function validate_email(field,alerttxt)
{
with (field)
{
apos=value.indexOf("@");
dotpos=value.lastIndexOf(".");
if (apos<1||dotpos-apos<2) 
  {alert(alerttxt);return false;}
else {return true;}
}
}




function validate_numeric(field,alerttxt)
{
   var ValidChars = "0123456789.";
   var IsNumber=true;
   var Char;
   var sText = field.value;
 
   for (i = 0; i < sText.length && IsNumber == true; i++) 
      { 
      Char = sText.charAt(i); 
      if (ValidChars.indexOf(Char) == -1) 
         {
         alert(alerttxt);
         return false;
         }
      }
   return true;
   
   }
   
var invalid_gen = '~!$%^&*(){}[]|":;<>?\'_';
var invalid_zip ='abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ~!$%^&*(){}[]|":;<>?\'_';

 
function validate_invalid(field,alerttxt,charchk) {
  val = field.value;
  if (val == "") return true;
  for (i=0; i<charchk.length; i++) {
    if (val.indexOf(charchk.charAt(i),0) > -1) 
    {
      alert(alerttxt);
      return false;
    }
  }
  return true;
}