Hi Dawa,

Try if this code will work for you:

CLEAR
CLEAR ALL

oForm = CREATEOBJECT("TForm")
oForm.Show(1)

DEFINE CLASS TForm As Form

	ADD OBJECT txt As TextBox WITH Left=5,;
	Top=10, Height=24, Width=100

	ADD OBJECT cmb As ComboBox WITH Left=5,;
	Top=30, Height=24, Width=100, Style=2

PROCEDURE Init
	DECLARE INTEGER ShowCursor IN user32 INTEGER bShow

PROCEDURE Destroy
	ThisForm._show

PROCEDURE cmb.Init
	THIS.AddItem("Anne")
	THIS.AddItem("Bob")
	THIS.AddItem("Chris")
	THIS.AddItem("Dan")
	THIS.AddItem("Evan")
	THIS.AddItem("Frank")
	THIS.AddItem("George")

PROCEDURE txt.GotFocus
	ThisForm._show

PROCEDURE cmb.GotFocus
	ThisForm._hide

PROCEDURE _hide
	DO WHILE ShowCursor(0) >= -1
		DOEVENTS
	ENDDO

PROCEDURE _show
	DO WHILE ShowCursor(1) < 0
		DOEVENTS
	ENDDO
ENDDEFINE

ShowCursor API is used to hide and show mouse pointer. When the pointer is hidden the mouse is still active. The code is kind of "fast and dirty", still it may help :)