var browserName = navigator.appName;
var browserRealnum = navigator.appVersion;
var browserNum = parseInt(navigator.appVersion);
var browserParsed = browserRealnum.substring(0,4);
var cipher = navigator.cipher;
var keySize = navigator.keySize;
var userAgent = navigator.userAgent;
var msBrowserVersion = browserParsed

var tel1Length = 2
var tel2Length = 2
var tel3Length = 3

var   invalidTEL = "Error Message UR004:\nThe Telephone Number you entered is not valid. Please re-enter your Telephone Number.";

if(browserName == "Microsoft Internet Explorer") 
{
  p = browserRealnum.indexOf("MSIE") + 5;
  f = browserRealnum.substring(p,p+1);

  if((f.indexOf(" ")!=-1) || (f.indexOf(";")!=-1))
  {
    f = browserRealnum.substring(p,p+3);
  }

  if (f >= 5.0)
  {
    tel1Length = 3
    tel2Length = 3
    tel3Length = 4
  }
}


function handleTabs(name)
{
  if (name == "txtTEL1") 
  {
    if ( ( !isInteger(document.getElementById("txtTEL1").value)))
    {
      alert(invalidTEL);
      document.getElementById("txtTEL1").focus();
    }
    else if ((isInteger(document.getElementById("txtTEL1").value)) &&(document.getElementById("txtTEL1").value.length == tel1Length)) 
    {
      document.getElementById("txtTEL2").focus();
    }
  }
  if (name == "txtTEL2")
  {
    if ( ( !isInteger(document.getElementById("txtTEL2").value)))
    {
      alert(invalidTEL);
      document.getElementById("txtTEL2").focus();
    }
    else if ( ( isInteger(document.getElementById("txtTEL2").value) ) &&( document.getElementById("txtTEL2").value.length == tel2Length  ) ) 
    {
      document.getElementById("txtTEL3").focus();
    }
  }
  if (name == "txtTEL3")
  {
    if ( ( !isInteger(document.getElementById("txtTEL3").value ) ) )
    {
      alert(invalidTEL);
      document.getElementById("txtTEL3").focus();
    }
    else if ( ( isInteger(document.getElementById("txtTEL3").value) ) &&( document.getElementById("txtTEL3").value.length == tel3Length ) ) 
    {
      document.getElementById("txtTEL3").focus();
    }
  }
}


function isInteger (s)
{   
    var i;
    for (i = 0; i < s.length; i++) {
        var c = s.charAt(i);
        if (!isDigit(c)) return false;
    }
    return true;
}

function isDigit (c)
{
   return ((c >= "0") && (c <= "9"))
}