Get Url Value by Variable Name

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.4/jquery.min.js"></script>

<script language="JavaScript" type="text/javascript">
  function getUrlValue(varSearch) {
      var searchString = window.location.search.substring(1);
      var variableArray = searchString.split('&');
      for (var i = 0; i < variableArray.length; i++) {
          var keyValuePair = variableArray[i].split('=');
          if (keyValuePair[0] == varSearch) {
              return keyValuePair[1];
          }
      }
  }

  $(document).ready(function(){
    var v = getUrlValue('lang');
    console.log(v);
  })
</script>

//access with url_javascript.html?lang=english