Random Objective-C Question

Just a quick question for any of you Objective-C programmers out there:

How do you determine if a pointer hasn't been allocated to an object?

For example, say I had the following declaration:

NSAttributedString	*attribString

I have coded a few If statements that *may* point that pointer to a new NSAttributedString object, but how would I be able to test if this pointer has actually been "pointed"? :P

I originally thought it would be something like:

if(attribString)

but that returns true no matter what, and so does

if(attribString!=NULL)

and

if(attribString!=Nil)

and

if(attribString!=nil)

It returns true in every case!


Anyone any ideas?