function getReference()
{
var refno = document.refConv.elements[0].value + "K"
var mod11 = 11 
weighting  = new Array(11)  // ignore char pos 0 and 10  
weighting[0] = 0;	weighting[1] = 6;	weighting[2] = 7;	weighting[3] = 8;	weighting[4] = 9
weighting[5] = 10;	weighting[6] = 5;	weighting[7] = 4;	weighting[8] = 3;	weighting[9] = 2;	weighting[10] = 0		
checkDigits = new Array(11)
checkDigits[0] = 2;	checkDigits[1] = 1;	checkDigits[2] = 9;	checkDigits[3] = 8
checkDigits[4] = 7;	checkDigits[5] = 6;	checkDigits[6] = 5;	checkDigits[7] = 4
checkDigits[8] = 3;	checkDigits[9] = 2;	checkDigits[10] = 1
var msgTxt = ""
reg = /\d{10}K/
var refno = refno.toUpperCase()
error_count = 0
if (reg.test(refno) == false) {
	//alert("SA Reference format invalid. The eleventh character is always 'K' and characters 1-10 are always numeric")
	error_count = error_count + 1
}
else {
	var total = 0
	for (var i = 0; i < 10; i++) {  // chars 1 and 10 ignored as per rules - zero  values should account
		hold = "" + refno.substring(i, i + 1);	total = total + hold * weighting[i]
	}
	var remainder = total%mod11
	if(checkDigits[remainder] == refno.substring(0,1)) {
		 //alert("SA Reference is correct")
		error_count = 0
	}
	else {
		//alert("SA Reference format invalid. Calculated check digit does not match actual check digit " + refno.substring(0,1))
		error_count = error_count + 1
	}
}
  if (error_count == 0) {alert("Your Reference number is correct.")} 
  else {
	var response = confirm("The reference number is incorrect. Press 'OK' for help or 'Cancel' to try again.")
	if (response) {window.location="/tools/payinghmrc/help/sa-help.htm"}
}

}



/******************/
function clearForm()
/*******************

   File        clearForm.jsm
   Copyright   Crown Copyright 2001

   Date        Author        Changes
   04-Jan-01   Chris Lowe    Created

   Purpose:
        To clear values from form fields. 

   Strategy:
        1. On clicking a button:
        2. Reset field values to null

   Input:
        none

   Output:
        none
--------------------------------------------------------------------- */
{


  document.refConv.elements[0].value = ""               // clear values
    

  return
}