This method GetSubwebsForCurrentUser always returns an SPWebCollection object
immaterial of the user  having rights  or not. But when i try to access  the
webCollection.Count it raises an exception., i.e.

the condition if ( !webCollection ) or if ( webCollection!=null ) evaluates to
true.

but if you try to do a webCollection.Count it throws an exception.

So how do i check if the SPWebCollection object is usable or not?