Create a form with a grid and one button

in the thisform.grid1.column1.text1.valid method :
if this.value > 1000
= messagebox("Incorrect Value")
return .f.
endif
return .t.

in the thisform.grid1.column1.text1.lostfocus method :
if this.value > 1000
this.value = 0
endif

So if you enter 1000 the messagebox appears then you click OK and if you click on the button the thisform.grid1.column1.text1.lostfocus
won´t be executed.

What´s happening here

I´m working with Vfp 5.0a

Thank you ALL