I was searching for a way in javascript by which I can get url query parameters and found this here : http://jsperf.com/querystring-with-javascript probably the best solution.

Get query string using fastest javascript method

<script>
  window.getParameterByName = function(name) {
   name = name.replace(/[\[]/, "\\\[").replace(/[\]]/, "\\\]");
   var regexS = "[\\?&]" + name + "=([^&#]*)";
   var regex = new RegExp(regexS);
   var results = regex.exec(window.location.href);
   if (results == null) return "";
   else return decodeURIComponent(results[1].replace(/\+/g, " "));
  }
</script>

usage: 

<script>
var search = window.getParameterByName("q");
var value = window.getParameterByName("value");
var undef = window.getParameterByName("undefinedstring");
</script>