使用id分配正确的值

I have a little quiz that asks when was the great depression. There are 4 divs that contain a decade, with 1920 being the correct answer (3rd div). In my jQuery I have put that any variable that has a value of 1920 = 'correct_answer' and that when it is clicked on there will be a message that reads 'correct'. Any other answer will alert 'wrong'. Why isn't this working? I have a little quiz that asks when was the gre