asp.net服务器向客户端弹出对话框，但不使页面边白板

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

public partial class ClientScript : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
        Response.Write("<script>alert('test1---直接Response输出')</script>");

        Page.ClientScript.RegisterClientScriptBlock(this.GetType(), "", "<script>alert('test2')</script>");

        if (!ClientScript.IsClientScriptBlockRegistered(this.GetType(), "ClientScriptBlock"));
        {
            ClientScript.RegisterClientScriptBlock(this.GetType(), "ClientScriptBlock", "<script>alert('test3---靠近<form>先弹出')</script>");
        }

        if (!ClientScript.IsStartupScriptRegistered(this.GetType(), "StartupScript"))
        {
            ClientScript.RegisterStartupScript(this.GetType(), "StartupScript", "<script>alert('test4---靠近</form>后弹出')</script>");
        }

    }
}

可以通过查看页面源码，看看有什么不同…