Radio Button List - VB.Net

Hello,
I have a radio button list with three options:
   Contact A,  Contact B, and Contact C
If none of them are selected I need to have a null value put into the table.  This is my code:
            If Owner_Primary_ContactRadBtnLst.SelectedValue = "" Then                 OICCmd.Parameters.Add("Primary_Contact", SqlDbType.Char).Value = ""             ElseIf Primary_ContactRadBtnLst.SelectedIndex = 0 Then                 OICCmd.Parameters.Add("@Primary_Contact", SqlDbType.Char).Value = "A"             ElseIf Primary_ContactRadBtnLst.Se ...