function track(){
  document.getElementById('error').value = '';
  var url = document.getElementById('track').value;
  urlArray = url.split("@@");
  if(url!=0){
    window.open(urlArray[1],'track','location=yes,status=yes,menubar=yes,scrollbars=yes,resizable=yes,width=975,height=600'); 
    document.getElementById('prefix').value = urlArray[0];
  }
}
function tracksea(){
  var url = document.getElementById('tracksea').value;
  if(url!=0){
    window.open(url,'track','location=yes,status=yes,menubar=yes,scrollbars=yes,resizable=yes,width=975,height=600'); 
  }
}

function pref(e,errormes){

  var numcheck;
  var prefix = document.getElementById('prefix').value;
  if(window.event) // IE
  {
    keynum = e.keyCode
  }
  else if(e.which) // Netscape/Firefox/Opera
  {
    keynum = e.which
  }
  if(keynum==13 || !keynum || prefix){
    var urlLenght = document.getElementById('track').options.length;
    for (var i = 0; i < urlLenght; i++){
      var urlOption = document.getElementById('track').options[i].value;
      urlArray = urlOption.split("@@");
      if (urlArray[0]==prefix){
        document.getElementById('track').value = urlOption;
        document.getElementById('error').value = '';
        window.open(urlArray[1],'track','location=yes,status=yes,menubar=yes,scrollbars=yes,resizable=yes,width=975,height=600'); 
      }
      else{
        document.getElementById('error').value = errormes;
      }
    }
  }
}