User-ID Validierung erfolgreich implementiert.

login/login_FLEX.aspx.vb

@@ -22,13 +22,19 @@ Partial Class login_FLEX
         Dim tb As TextBox = form1.FindControl("UserID")
         Dim reqfieldvaluserID As RequiredFieldValidator = Page.FindControl("CustomerIDrequired")
         reqfieldvaluserID.Validate()
+        Dim user_ID As String
+        If reqfieldvaluserID.IsValid Then
+            user_ID = tb.Text
+        Else
+            user_ID = ""
+        End If
         ' Dim constr As String = ConfigurationManager.ConnectionStrings("constr").ConnectionString
         Using con As New SqlConnection(ConnectionString)
             ' Using cmd As New SqlCommand("Validate_User")
             Using cmd As New SqlCommand("SELECT COUNT(*) FROM [VERAG_HOMEPAGE].[dbo].[Users] WHERE Username=@Username AND Password=@Password AND Kundennr=@UserID")
                 ' cmd.CommandType = CommandType.StoredProcedure
                 cmd.Parameters.AddWithValue("@Username", Login1.UserName)
-                cmd.Parameters.AddWithValue("UserID", tb.Text)
+                cmd.Parameters.AddWithValue("UserID", user_ID)
                 cmd.Parameters.AddWithValue("@Password", Login1.Password)
                 cmd.Connection = con
                 con.Open()