下面的代码应该如何改才能让页面显示的不是空白

下面的代码应该怎么改才能让页面显示的不是空白?
Private   Sub   cmdSearch_Click(ByVal   sender   As   System.Object,   ByVal   e   As   System.EventArgs)   Handles   cmdSearch.Click
                'Gridlist.CurrentPageIndex   =   0
                'dlapdept.SelectedValue   =   " "
                'ddlRecdept.SelectedValue   =   " "
                'txtRecLocation.Text   =   " "
                'txtRecuser.Text   =   " "
                'txtappdate.Value   =   " "
                'txtOrder.Text   =   " "
                'txtSaddress.Text   =   " "
                'txtmeno.Text   =   " "
                If   txtSearchcode.Text   =   " "   Then
                        Response.Write( " <script   language= 'javascript '>   alert( '搜索单号不能为空,请输入申请表主单号进行查询! '); </script> ")
                        'Response.Write( " <script   language= 'javascript '> ")
                        'Response.Write( "alert( '搜索单号不能为空,请输入申请表主单号进行查询! '); ")
                        'Response.Write( " </script> ")
                        Exit   Sub
                End   If
                GridbindSerch()
                Griddetailbindsearch()
        End   Sub

上面的语句在提示框跳出来的时候页面总全是白色的很难看,怎么改才能保持提示框跳出来时原来的页面还是显示以前的内容?

------解决方案--------------------


'Response.Write( " <script language= 'javascript '> ")
to
'Response.Write( " <script language= 'javascript ' defer> ")
------解决方案--------------------
Literal le = new Literal();
this.Controls.Add(le);
le.Text= " <script language= 'javascript '> alert( '搜索单号不能为空,请输入申请表主单号进行查询! '); </script> ";
------解决方案--------------------
page.ClientScript.RegisterStartupScript(page.GetType(), "alert ",
"alert( '搜索单号不能为空,请输入申请表主单号进行查询! '); ",true);