function createXMLHttpRequest(){
if(window.ActiveXObject){
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}else {
xmlHttp = new XMLHttpRequest();
}
}
function showEnter(){
createXMLHttpRequest();
xmlHttp.onreadystatechange = showContent;
var url = "b.aspx";//去后台取数据库的值,也可以在数据库进行比较。
xmlHttp.open("GET", url, true);
xmlHttp.send(null);
}
function showContent(){
if(xmlHttp.readyState == 4){
if(xmlHttp.status ==200){
var ret = xmlHttp.responseText;
document.getElementById("divReturn").innerHTML = ret;