Swapping same class for different time

<p>I am registered in one class that is full and I want to go into another one that is full. Assuming that the one that I want to go into opens up can I use the option :</p>

<p>xxx Drop upon successfully adding yyy ?</p>

<p>I was wondering if it would try to add first and just reject it since I am already registered for that class or would the system be smart enough to recognize it is a swap of the same class thus allowing it ?</p>

<p>Or should I use Drop and then Add ? This is a little scarier as I can drop it and then the other one would be full and thus I could end up with no class</p>

<p>Thank YOU !</p>

<p>The system will be “smart enough”. lol</p>

<p>It will only drop X if Y can successfully be added, assuming X is dropped.</p>