Print หน้าเว็บเพจล้นหน้ากระดาษมีวิธีย่อขนาดให้พอดีหน้ากระดาษได้อย่างไรครับ

Imports System
Imports System.Data
Imports System.Configuration
Imports System.Web
Imports System.Web.Security
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.WebControls.WebParts
Imports System.Web.UI.HtmlControls
Imports System.IO
Imports System.Text
Imports System.Web.SessionState

Public Class PrintHelper
    Public Sub New()
    End Sub

    Public Shared Sub PrintWebControl(ByVal ctrl As Control)
        PrintWebControl(ctrl, String.Empty)
    End Sub

    Public Shared Sub PrintWebControl(ByVal ctrl As Control, ByVal Script As String)
        Dim stringWrite As StringWriter = New StringWriter()
        Dim htmlWrite As System.Web.UI.HtmlTextWriter = New System.Web.UI.HtmlTextWriter(stringWrite)
        If TypeOf ctrl Is WebControl Then
            Dim w As Unit = New Unit(100, UnitType.Percentage)
            CType(ctrl, WebControl).Width = w
        End If
        Dim pg As Page = New Page()
        pg.EnableEventValidation = False
        If Script <> String.Empty Then
            pg.ClientScript.RegisterStartupScript(pg.GetType(), "PrintJavaScript", Script)
        End If
        Dim frm As HtmlForm = New HtmlForm()
        pg.Controls.Add(frm)
        frm.Attributes.Add("runat", "server")
        frm.Controls.Add(ctrl)
        pg.DesignerInitialize()
        pg.RenderControl(htmlWrite)
        Dim strHTML As String = stringWrite.ToString()
        HttpContext.Current.Response.Clear()
        HttpContext.Current.Response.Write(strHTML)
        HttpContext.Current.Response.Write("<script>window.print();</script>")
        HttpContext.Current.Response.End()
    End Sub

End Class

    Protected Sub imgBtnPrint_Click(ByVal sender As Object, ByVal e As System.Web.UI.ImageClickEventArgs) Handles imgBtnPrint.Click
        Session("ctrl") = Panel1
        ClientScript.RegisterStartupScript(Me.GetType(), "onclick", "<script language=javascript>window.open('Print.aspx','PrintMe','height=300px,width=300px,scrollbars=1');</script>")
    End Sub

<asp:panel id="panel1" runat="server">
----------Gridview----------
</asp:panel>