function getQueryVariable(variable) { 
  var query = window.location.search.substring(1); 
  var vars = query.split("&"); 
  for (var i=0;i<vars.length;i++) { 
    var pair = vars[i].split("="); 
    if (pair[0] == variable) { 
      return pair[1]; 
    } 
  }
  
  return "";
}