access stored proc value from vb.net

I have a stored proc named  spTierCredits_PlayerID
(I am passing in an input parameter named playerid)

 that does a bunch of processing to dettermine an end value for

DECLARE @TotalTableSlotTierCredits AS DECIMAL(18, 2);

....
 

SET @TotalTableSlotTierCredits = isnull(@TotalTableTierCredits,0) + isnull(@TotalSlotTierCredits,0)

From what I have read I should be able to get this in a vb.net app without defining
@TotalTableSlotTierCredits  as an output variable.

I am having some trouble though


 strConn = ConfigurationManager.ConnectionStrings("DBConnectStringPlayerTierInfo").ConnectionString
            Dim cn As New SqlClient.SqlConnection(strConn)

            cn.Open()

            Dim strsql As String
            strsql = "spTierCredits_PlayerID"
            Dim param As New SqlClient.SqlParameter
            Dim cmd As New SqlClient.SqlCommand(strsql, cn)
            cmd.CommandType = CommandType.StoredProcedure
            param = cmd.Parameters.Add("@playerid", SqlDbType.VarChar, 0)
         
            cmd.Parameters(0).Value = intPlayerid
            Dim rdr As SqlClient.SqlDataReader = cmd.ExecuteReader()

            If rdr.Read() = False Then
                lblFeedback.Text = "No Player Id found for card swiped"
                lblFeedback.CssClass = "errorMsg"
                divFeedbackHolder.Visible = True
                lblTotalTierCreditsValue.Text = ""
                rdr.Close()
                txtCardID.Text = ""
                Exit Sub
            Else
                intPlayerid = rdr.Item("PlayerID")
            End If

            rdr.Close()

            cn.Close()
            txtCardID.Text = ""