parameters in response redirect is not working

Hi

I have the below code in the master page(header), where the user click the searchbox

 Private Sub LinkButton1_Click(sender As Object, e As System.EventArgs) Handles LinkButton1.Click

        Dim ab As String
        ab = Trim(Searchbox.Text)

        Response.Redirect("/Storeview/p171/St=" & ab)

end sub

and im getting the St variable as blank in redirect page.. Wht should i do? thanks