Redirect a page when listbox is empty

I am trying to redirect a page, so that when they are finished paying all individuals on page it redirects to another page.  Right now a list box populates with names that dissapear each time the user pays one.  At the end when the list box is empty I want it to redirect to another page.  how do i do this.   The follwoing is my submit button code.

Private Sub btnSubmit_Click(ByVal sender As Object, ByVal e As System.EventArgs) Handles btnSubmit.Click

        Dim ids As String = Replace(Request.Form("hidIDs"), " ", "")
        Dim id As String

        Do While ids <> ""
            id = Left(ids, InStr(ids, ",") - 1)
            ids = Right(ids, Len(ids) - InStr(ids, ","))

            insertUpdateDelete("update tblAssignedPersonnel set dtPayProcessed = '" & Date.Now & "', " _
                             & "intMileage = '" & Request.Form("txtMileage" & id) & "' where intAssignedPersonnelID = " & id)
        Loop

        Clearlabels()   ( This clears labels on the page)
        getSoldiers()   (This repopulates the list page)
    End Sub