ajax web页面复杂处理延时、客户交互问题

<script type="text/javascript">
function Wait()
{
var child=document.createElement("div");
child.id="looder";
child.style.top =300;
child.style.left = 300;
child.style.position="absolute";
child.innerHTML="<img src='../img/loadingAnimation.gif'/>";

document.body.appendChild(child);
child.focus();

}
</script>
this.Button1.Attributes.Add("onclick", this.Page.ClientScript.GetPostBackEventReference(Button1, "Click") + ";this.disabled=true; this.value='初始化..';Wait();");