>>>Hi,
>>>
>>>I have a form to which I add several container objects or remove existing container objects. When the form is resized the current existing objects will be re-arranged in order to show as many as possible horizontally without needing to scroll and then moving down the form if more space is required. i.e. a vertical scroll bar will become added as more objects are added. Sometimes objects can be removed from the form.
>>>
>>>Generally this works as required. However, sometimes when the form is resized or objects added/removed VFP suddenly displays a black area on the form from a random point downwards to the bottom of the form. This whole area is just black. Resizing the form, which triggers the resize event, re-displays the form objects properly again. Any idea what this black area is and how to prevent it occuring?
>>>
>>>TIA
>>
>>Try either thisform.cls() or thisform.draw() after you add objects.
>
>No I spoke too soon. Should I use one, the other or both and when? Before/after each object or only after all objects have been set and arranged?

With thisform.draw and thisform.cls there is no definite answer - you apply it on case by case basis. If you found it's enough to put thisform.draw() after you added all objects and then this effect doesn't occur anymore, then it would be fine, I assume. Otherwise you may try adding it until you're certain no more problems occur.