dealloc is called as a result of memory management. Once an objects “retainCount” reaches 0 then a dealloc message is automatically sent to that object.
You should never call dealloc on objects unless it is a call to [super dealloc]; at the end of an overridden dealloc.
[ivar release]; //Release any retained variables before super dealloc
[super dealloc]; //Only place in your code you should ever call dealloc