>>>I have a toolbar called mytoolbar in a classlib called myclasslib
>>>I want to make my toolbar invisible.
>>
>>It doesn't matter what is class name and even library name. However it does matter how you called the object (name property) instanciating from the class. This name should be used in reference, e.g. if toolbar 'tbMain' is part of formset, you use Thisformset.tbMain.Hide
>
>thanks Ed - Actually, I am in a stand alone form and I want to
>set visible = .f. to a toolbar that is part of a formset.

In this situation your problem is to reference formset. Rresumably it will work using:
frsMain.tbMain.Visible=.f. && I assume that you started formset DO FORM form1 NAME frsMain LINKED