select a value from a dropdownlist inside an itemtemplate in a GridView

Hi,
I have a GridView with a templatefield that contains a dropdownlist. I want to insert the selectedvalue as a datetime field into a table.
This is my code:


Protected Sub GridView1_RowDataBound(ByVal sender As Object, ByVal e As GridViewRowEventArgs) Handles GridView1.RowDataBound
        If e.Row.RowType = DataControlRowType.DataRow Then
            Dim shippingdate As DateTime
            For i = 0 To 5
                shippingdate = Now.AddDays(i)
                DirectCast(e.Row.FindControl("ddlShippingDate"), DropDownList).Items.Add(shippingdate)
             ...