ToolTipText

hi all
how can we have teh tooltiptext being disabled? not set them to "" is DISABLE it.. i know some control can be done, how about picture box and MSFLEXGRID? do we have api to control teh tooltiptext in msflexgrid or other control?
Also, i found a problem when i try to display the tooltiptext for certain column in msflexgrid and set others to "" a small visible box appreaer... can anyone gives me suggestion?
codes
Private Sub Form_Load()
MSFlexGrid1.Rows = 4
MSFlexGrid1.Cols = 3
For i = 1 To 3
MSFlexGrid1.TextMatrix(i, 0) = i
Next i
End Sub
Private Sub MSFlexGrid1_MouseMove(Button As Integer, Shift As Integer, x As Single, y As Single)
If x <= MSFlexGrid1.ColWidth(0) Then
Position = y / MSFlexGrid1.RowHeight(0)
Select Case Position
Case Is <= 1
Case Is <= 2
MSFlexGrid1.ToolTipText = "name 1 defination"
Case Is <= 3
MSFlexGrid1.ToolTipText = "name 2 defination"
Case Is <= 4
MSFlexGrid1.ToolTipText = "name 3 defination"
Case Else
MSFlexGrid1.ToolTipText = ""
End Select
Else
MSFlexGrid1.ToolTipText = ""

End If
End Sub

* move the mouse from left to right... you will see the box...

thanks
* please see the print font question also..
thanks again