asp上传带显示的代码

注意是用到了，下列的演示
<script language="javascript" type="text/javascript">
adtime=8;
chancead=1;
var ns=(document.layers);
var ie=(document.all);
var w3=(document.getelementbyid && !ie);
adcount=0;
function initad(){
        if(!ns && !ie && !w3) return;
        if(ie)                addiv=eval('document.all.sponsoraddiv.style');
        else if(ns)        addiv=eval('document.layers["sponsoraddiv"]');
        else if(w3)        addiv=eval('document.getelementbyid("sponsoraddiv").style');
        randad=math.ceil(math.random()*chancead);
        if (ie||w3)
        addiv.visibility="visible";
        else
        addiv.visibility ="show";
        if(randad==1) showad();
}
function showad(){
if(adcount<adtime*10){adcount+=1;
        if (ie){documentwidth  =document.body.offsetwidth/2+document.body.scrollleft-20;
        documentheight =document.body.offsetheight/2+document.body.scrolltop-20;}
        else if (ns){documentwidth=window.innerwidth/2+window.pagexoffset-20;
        documentheight=window.innerheight/2+window.pageyoffset-20;}
        else if (w3){documentwidth=self.innerwidth/2+window.pagexoffset-20;
        documentheight=self.innerheight/2+window.pageyoffset-20;}
        addiv.left=documentwidth-100;addiv.top =documentheight-0;
        settimeout("showad()",100);}
}
function closead(){
if (ie||w3)
addiv.display="none";
else
addiv.visibility ="hide";
}
function $(obj){
    return document.getelementbyid(obj);
}

function checkform(){
    if($("file1").value != "")
    {
                if(/jpg|jpeg|gif|bmp/i.test($("file1").value.match(/\.(\w+)$/)[0]) == false){
                    alert("您只能上传图片文件");
                    return false;
                }
                else
                {
                    return true;
                }
    }
    else
    {
        alert("您还没有选中需要上传的图片");
        return false;
    }
}