var xmlHttp = false;
try {
  xmlHttp = new ActiveXObject("Msxml2.XMLHTTP");
} catch (e) {
  try {
    xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
  } catch (e2) {
    xmlHttp = false;
  }
}
if (!xmlHttp && typeof XMLHttpRequest != 'undefined') {
  xmlHttp = new XMLHttpRequest();
}

function callServer() {
  var user_name = document.getElementById("user_name").value;
  if ((user_name == null) || (user_name == "")) return;
  var url = "ajax/cu.asp?user_name=" + escape(user_name);
  xmlHttp.open("GET", url, true);
  xmlHttp.onreadystatechange = updatePage;
  xmlHttp.send(null);  
}

function updatePage() {
  if (xmlHttp.readyState < 4) {
	test1.innerHTML="loading...";
  }
  if (xmlHttp.readyState == 4) {
    var response = xmlHttp.responseText;
	test1.innerHTML=response;
  }
}