VS 2008 Space invaders end

I'm building a Space Invaders game, i reached the point when the user will lose if any of the pictureboxes( Aliens) touches the lower limit. my code is a following but it isn't working:
( i have 28 pictureboxes or as i called them Aliens)

For X = 1 To 28
If Aliens(X).Height >= Me.Height - 5 Then
MoveT1.Enabled = False
MsgBox("You lose!")
End If
Next

i guess the problem is in : If Aliens(X).Height >= Me.Height - 5 Then
Any advices?