class is full

[YutianCai]

Hi,

I droped one of my courses and reselected another one just now. However,when I try to select a new time, all of them are full, so I can't choose anyone. Can I still join in this course or I can not, could somebody thell me? THANKS!

（I noticed that the system says use the swap function (heart), but I am not sure what and where is it.)