Unknown error when adding items to DropDownListBox

Hi,

Due to requirements, I have to add a brand new DropDownListBox in my current webpage.

I need to add items at the behind-code, which is as follows,   While True
Dim name As String = ReadIni(setting, "Protocol", "Name" + counter.ToString)
Dim id As String = ReadIni(setting, "Protocol", "Id" + counter.ToString)
If name = "" Then
Exit While
End If
DropDownList1.Items.Add(New ListItem(name, id))
counter = counter + 1
End While
When I try to run the website from the Visua ...