JS: get params in url query string

get_params.js

  function getParameterByName( 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, " "));
  }