function load() { 

var xmlhttp; 
if (window.XMLHttpRequest) 
  {// code for IE7+, Firefox, Chrome, Opera, Safari 
  xmlhttp=new XMLHttpRequest(); 
  } 
else 
  {// code for IE6, IE5 
  xmlhttp=new ActiveXObject("Microsoft.XMLHTTP"); 
  } 

  xmlhttp.onreadystatechange = readyDo; 
  xmlhttp.open("POST", "http://localhost:28732/default.aspx", true); 
  xmlhttp.setRequestHeader("Content-Type", "application/x-www-form-urlencoded; charset=UTF-8"); 
  xmlhttp.send("a=aa&b=123"); 
  } 

  function readyDo() { 
  if (xmlhttp.readyState == 4) { 
  if (xmlhttp.status == 200) { 
  alert(xmlhttp.responseText); 
  displayDiv.innerHTML = xmlhttp.responseText; 
  } 
  } 
  else { 
  displayDiv.innerHTML = "正在加载.."; 
  } 
  }