See the screenshot, there's an X on the left, and an X on the right.
Sometimes I forget which one I'm supposed to click (Windows has an X on the right, but Mac has an X on the left of window borders for example).
|Field||Original Value||New Value|
|Assignee||Brody Maclean [ brody ]|
|Issue Type||Bug [ 1 ]||Task [ 3 ]|