Visual Basic

<br />
for each item as control in form.controls<br />
  if item.GetType is GetType(ComboBox) then<br />
     if item.Text = "" then<br />
        errorPro.SetError(cbos, "Do not leave the factor box empty!")<br />
     end if<br />
  end if<br />
next<br />

Private Function checkCbos() As Boolean<br />
Dim myControl As Control<br />
<br />
For Each myControl In Me.Controls<br />
   If TypeOf myControl Is ComboBox Then<br />
      If myControl.Text = "" Then<br />
      'Set error provider<br />
      errorPro.SetError(myControl, "Do not leave the factor box empty!")<br />
      'Return False and exit to calling procedure      <br />
      Return False<br />
      Else<br />
      'Clear the error provider<br />
      errorPro.SetError(myControl, "")      <br />
      End If<br />
   End If<br />
Next myControl<br />
<br />
'If code gets to here, no combo's text is ""<br />
Return True<br />
<br />
End Function

    Dim hostInfo As IPHostEntry = Dns.GetHostByName("www.yahoo.com")
    Dim address As IPAddress() = hostInfo.AddressList
 
    Dim al As String() = hostInfo.Aliases
    Debug.WriteLine("Host name : " + hostInfo.HostName)
    Debug.WriteLine(ControlChars.Cr + "Aliases : ")
 
    Dim index As Integer
    For index = 0 To al.Length - 1
        Debug.WriteLine(al(index))
    Next index
 
    Debug.WriteLine(ControlChars.Cr + "IP address list : ")
    For index = 0 To address.Length - 1
        Debug.WriteLine(address(index))
    Next index