查看上传的文件asp.net c#

protected void Button2_Click(object sender, EventArgs e)
{
if (DropDownList1.SelectedIndex>0)
{
Session["kk"] = this.DropDownList1.SelectedValue.Trim().ToString();

Response.Redirect("uplist.aspx");
}
else
{
Page.ClientScript.RegisterStartupScript(Page.GetType(), "message", "");
return;
}

 

}