//alert(document.getelementbyid(depcode).value);
//alert(document.getelementbyid(querytype).value);
var querystring =deptcode+ = +deptcode;
querystring+= &querytype + = + querytype;//如果有多个参数需要传递,则用&符号连接
xmlhttp.open(post, url, true);
xmlhttp.onreadystatechange = showipsearchresult;
xmlhttp.setrequestheader(content-type, application/x-www-form-urlencoded;);
xmlhttp.send(querystring);