Hi David
Thank u very much for ur explanation.
may be u can give me ur expert advise here.

I have class(say clsparent) with (container,textbox and a commandbtn) and i set controlsource property of the textbox to tabname.fldname.

now i subclassed the abv class (say chldClass) .When i add this class (i.e chldClass)
on a form thr code i get the error i specified in my initial post.
i blanked out textbox control source property in subclass everything works fine but, as u know ,textbox does not show anything.
i tried assigning controlsource in init() and load() but to no avail.
can u give me some advise on this plz.
many thanks