Get Querystring with Javascript...

function getUrlParams() {

  var paramMap = {};
  if (location.search.length == 0) {
    return paramMap;
  }
  var parts = location.search.substring(1).split("&");

  for (var i = 0; i < parts.length; i ++) {
    var component = parts[i].split("=");
    paramMap [decodeURIComponent(component[0])] = decodeURIComponent(component[1]);
  }
  return paramMap;
}

Then you could do the following to extract id from the url /hello.php?id=5&name=value

var params = getUrlParams();
var id = params['id']; // or params.id

For Reference....