Hi Marcia,
I had try out the coding but the data in the grid still no change after click the different of grid header with particular order. I had try to add in below code to let the grid repaint.

Header's Click method:

WITH This.Parent
IF PEMSTATUS( .Parent, 'SetOrder', 5 )
.Parent.SetOrder( JUSTEXT( .ControlSource ) )
.refresh && add in by Vincent
ENDIF
ENDWITH

But no effect!

If I want to click the grid header first time the order will be ascending order and click second time the order will be descending order. Can I write the code like this:

lnClick is public variable

IF lnClick = 1 THEN
SET ORDER TO ( tcTag ) ASCENDING
lnClick = 2
ELSE
SET ORDER TO ( tcTag ) DESCENDING
lnClick = 1
ENDIF

Pls help me again. Thank you very much.