How can I include address bar variable in this javascript line?

Question

Can someone please tell me how I can add in the address bar variable to my javascript?

The website address reads: www.example.com/index.php?user=74

and the javascript that needs to include 'user = 74' is:

xmlhttp.open("GET","../profile/" + pageName + ".php",true);

Answer 1

function get_query(){
  var url = location.href;
  var qs = url.substring(url.indexOf('?') + 1).split('&');
  for(var i = 0, result = {}; i < qs.length; i++){
    qs[i] = qs[i].split('=');
    result[qs[i][0]] = decodeURIComponent(qs[i][1]);
  }
  return result;
}

xmlhttp.open("GET","../profile/" + pageName + ".php?user=" + get_query()['user'],true);