Code:
  '
  '
Dim DataSent As Boolean
  '
  ' Other declarations, etc
  '
Private Sub FormLoad()
  '
 DataSent = True
  '
  ' 
  '
End Sub

Private Sub cmdSend(.....)
  '
  '
 If DataSent Then
   DataSent = False
   Winsock1.sendData data
 End If
  '
  '
End Sub
  '
  ' Other Subs, etc
  '
Private Sub Winsock1_SendComplete()
 DataSent = True
End Sub