asp+ajax聊天室常用js代码

//ajax
function getObject(objectId) {
if(document.getElementById && document.getElementById(objectId))
{
// W3C DOM
return document.getElementById(objectId);
}
else if (document.all && document.all(objectId))
{
// MSIE 4 DOM
return document.all(objectId);
}
else if (document.layers && document.layers[objectId])
{
// NN 4 DOM.. note: this won't find nested layers
return document.layers[objectId];
}
else
{
return false;
}
}
// CreateXMLHttpRequest
function CreateXMLHttpRequest()
{
// Initialize Mozilla XMLHttpRequest object
var xmlHttp;
if (window.XMLHttpRequest)
{
xmlHttp = new XMLHttpRequest();
}
// Initialize for IE/Windows ActiveX version
else if (window.ActiveXObject)
{
try
{
xmlHttp = new ActiveXObject("Msxml2.XMLHTTP.3.0");
}
catch (e)
{
try
{
xmlHttp = new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e)
{
newsstring = "对不起，您的浏览器不支持XMLHttpRequest对象！";}
}
}
return xmlHttp;
}

function getDataTimes()
{
var strDate,strTime;
strDate = new Date();
strTime = strDate.getTime();
return strTime;
}

//获取信息
function ShowMess()
{
var strtime = getDataTimes();
var url="mess.asp?strTime="+strtime;
var requestType = "mess_box";
var xmlHttp=CreateXMLHttpRequest();
xmlHttp.open("GET", url, true);
xmlHttp.onreadystatechange = function()
{
if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
{
getObject(requestType).innerHTML = xmlHttp.responseText;
}
}
xmlHttp.setRequestHeader("If-Modified-Since","0");
xmlHttp.send(null);
$();
online();

}
//发送信息
function SendMess()
{
var strtime = getDataTimes();
var mess = escape(document.getElementById('mess').value);
var mtowho = escape(document.getElementById('mtowho').value);
var mfont = escape(document.getElementById('mfont').value);
var mfcolor = escape(document.getElementById('mfcolor').value);
var elist = escape(document.getElementById('elist').value);
if (mess=="")
{
alert("不能发空信息！");
return false;
}
var url="SendMess.asp?mess="+mess+"&mtowho="+mtowho+"&mfont="+mfont+"&mfcolor="+mfcolor+"&elist="+elist+"&strTime="+strtime;
var xmlHttp=CreateXMLHttpRequest();
xmlHttp.open("get", url, true);
xmlHttp.send(null);
ShowMess();
document.getElementById('mess').value="";

}
//刷新
function getmess()
{
time=window.setInterval("ShowMess()",2000);
}
//检查是否离开
function $() {
var strtime = getDataTimes();
var url="k.asp?strTime="+strtime;
var xmlHttp=CreateXMLHttpRequest();
xmlHttp.open("GET", url, true);
xmlHttp.onreadystatechange = function()
{
if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
{
if (xmlHttp.responseText=="showScreen"){
showScreen();
}
}
}
xmlHttp.setRequestHeader("If-Modified-Since","0");
xmlHttp.send(null);
}
// 获取宽度
function getWidth()
{
var strWidth,clientWidth,bodyWidth;
clientWidth = document.documentElement.clientWidth;
bodyWidth = document.body.clientWidth;
if(bodyWidth > clientWidth){
strWidth = bodyWidth + 20;
} else {
strWidth = clientWidth;
}
return strWidth;
}
//获取高度
function getHeight()
{
var strHeight,clientHeight,bodyHeight;
clientHeight = document.documentElement.clientHeight;
bodyHeight = document.body.clientHeight;
if(bodyHeight > clientHeight){
strHeight = bodyHeight + 30;
} else {
strHeight = clientHeight;
}
return strHeight;
}
// 锁屏
function showScreen()
{
var Element = getObject('Message');
var Elements = getObject('Screen');
Elements.style.width = getWidth();
Elements.style.height = getHeight();
Element.style.display = 'block';
Elements.style.display = 'block';
getObject('mfont').disabled = true;
getObject('mfcolor').disabled = true;
getObject('elist').disabled = true;
}
//解屏
function hideScreen()
{
var Element = getObject('Message');
var Elements = getObject('Screen');
Element.style.display = 'none';
Elements.style.display = 'none';
getObject('mfont').disabled = false;
getObject('mfcolor').disabled = false;
getObject('elist').disabled = false;

}
//提交名称
function chkuser()
{

var strtime = getDataTimes();
var userid = escape(document.getElementById('userid').value);
var ischk;
if (userid=="")
{
alert("请输入名称！");
return false;
}
var url="user.asp?userid="+userid+"&strTime="+strtime;
var xmlHttp=CreateXMLHttpRequest();
xmlHttp.open("get", url, true);
xmlHttp.onreadystatechange = function()
{
if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
{
if (xmlHttp.responseText=="no"){
getObject("errmeg").innerHTML="你的名称已占用";
}
else
{
hideScreen();
}
}
}
xmlHttp.send(null);
}
//显示 在线人数
function online()
{

var strtime = getDataTimes();
var url="online.asp?strTime="+strtime;
var xmlHttp=CreateXMLHttpRequest();
var requestType = "on_line";
xmlHttp.open("get", url, true);
xmlHttp.onreadystatechange = function()
{
if (xmlHttp.readyState == 4 && xmlHttp.status == 200)
{
getObject(requestType).innerHTML=xmlHttp.responseText;
}
}

xmlHttp.setRequestHeader("If-Modified-Since","0");
xmlHttp.send(null);

}
//选择对话人
function mtowho(mtowho){
var requestType="mtowho";
getObject(requestType).value=mtowho;
}