//Return the value of a given query string variable
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];
	}
  } 
  //alert('Query Variable ' + variable + ' not found');
}