VB Code:
  1. Option Explicit
  2. Private StopIt As Boolean
  3.  
  4. Private Sub cmdCancel_Click()
  5. StopIt = True
  6. End Sub
  7.  
  8. Private Sub cmdDoTheLoop_Click()
  9.     Dim i As Long
  10.       For i = 1 to 1000000
  11.             'do your loop
  12.             DoEvents
  13.             If StopIt = True Then Exit For
  14.       Next
  15. End Sub