isValid = true;
var isNN = (navigator.appName.indexOf("Netscape") != -1);
if (isNN)
  document.captureEvents(Event.KEYPRESS);
  
function AutoTab(input,len, e)
{
  var keyCode = (isNN)?e.which:e.keyCode; 
  var filter = (isNN)?[0,8,9]:[0,8,9,16,17,18,37,38,39,40,46];
  
  if (input.value.length >= len && !containsElement(filter,keyCode))
  {
    input.value = input.value.slice(0,len);
    input.form[(getIndex(input)+1)%input.form.length].focus();
    input.form[(getIndex(input)+1)%input.form.length].select();
  }
  
  function containsElement(arr, ele)
  {
    var found = false, index = 0;
    while(!found && index < arr.length)
      if(arr[index]==ele)
        found = true;
      else
        index++;
    return found;
  }
  
  function getIndex(input)
  {
    var index = -1, i = 0, found = false;
    while (i < input.form.length && index==-1)
      if (input.form[i] == input)index = i;
      else i++;
    return index;
  }
  return true;
}