I don't have the chance to test it, but you can replace controlsource with the name of the field, if it's only used once. =!Empty(yourtable.yourfield). Note the !.

BTW, I gave you a misleading tip. This.controlsource will point to the name of the field, which will never be empty. !Empty(Evaluate(this.controlsource)) or !Empty(Evaluate(this.parent.controlsource)) should work, if you put it in the visible property of the commandbutton. And remember to remove or make invisible the default textbox in the column.

>OK
>I found the place for code but I got a 'syntax error' message by the expression builder.
>I tried this 3 option and I got alwais the message:
>

Empty(this.controlsource)
>!Empty(this.controlsource)
>=!Empty(this.controlsource)