Extracting data from cells in same row as a specific value.

Hi all.

I'm really stumped with this.

https://docs.google.com/spreadsheets...it?usp=sharing


Basically, I have column A with Box Names and column B with numbers. On another sheet, I need to pull out the Box Names with 13 as their number. It needs to be a condensed list, so the first however many cells in the other sheet should be the names of the Boxes with 13 as their numbers, and the list should update whenever a Box loses or gains a number that makes it something other than 13.


Thanks, I think this one is pretty tough :/