Asp.Net中弹出窗口

1、----------------------------------------------------------------

private string search_class()
{
switch (Convert.ToInt32(ddl_search.SelectedValue))
{
case 0:
return "software.aspx?class=0";
case 1:
return "drivesoftware.aspx?class=1";
case 2:
return "software.aspx?class=2";
case 3:
return "news.aspx?class=3";
case 4:
return "news.aspx?class=4";
case 5:
return "news.aspx?class=5";
case 6:
return "news.aspx?class=6";
default:
return "search.aspx";
}
}

private void ibt_search_Click(object sender, System.Web.UI.ImageClickEventArgs e)
{
Session["search_str"]=tb_search.Text.Replace("'","''");
Page.RegisterStartupScript("script","<script>window.open('"+search_class()+"')</script>");
}

以上是我的程序代码,ddl_search是下拉列表框.

2、-------------------------------------------------
private void Page_Load(object sender, System.EventArgs e)
  {
   // 在此处放置用户代码以初始化页面
   Button1.Attributes.Add("onclick","window.showModalDialog('webform1.aspx');return false;");
  }

3、-------------------------------------------------
private void Button1_Click(object sender, System.EventArgs e)
  {
   Response.Write("<script Language=javascript>window.showModalDialog('webform1.aspx');</script>");
   Response.Flush();
  }