label did not display anything even there is a value inside

hi , juz want to ask, why the msg that stored in the label wasn;t preview in the web ? wat's wrong
my aspx :
<asp:Label ID="lblMsg" runat="server"></asp:Label>
my aspx.vb:
For j As Integer = 0 To GridViewRDR1.Rows.Count - 1
     itemCodeRDR1 = GridViewRDR1.Rows(j).Cells(1).Text()    
If itemCodeRDR1 = itemCodeHidden Then
         msg = "Duplicate record for " & itemCodeHidden      
Exit For    
 Else        
msg = ""
     End If    
Next  
 If msg.Length > 0 Then  
 lblMsg.Text = msg     <=== here, msg was stored inside this label
Exit Sub    
End If
...