>>Try:
>
>>thisform.Grid1.Column.DynamicInputMask = "IIF(TheField%1=0,'9999','9999.999')"
>>Not tested.
>
>TESTED
>
>Not what I wanted to do but I found the way.
>
>Your solution makes a record not int is shown with decimals, integer without decimals. Perfect.
>
>What I wanted to do was: Just one with decimals? Everyone with decimals.

Then add a property to the form, something like this

locate for TheField%1#0
thisform.addproperty("hasNoDecimals", not found())
thisform.oGrid.DynamicInputMask = "IIF(thisform.hasNoDecimals,'9999','9999.999')"