How do you get past level 1 in causality

First click on the guy stood on the left of the roof, he'll fall off and die. Then the guy on the right of the roof has a metal pole next to him click it and it will fall on him and kill him. Meanwhile a guy would have got in the lift and gone upstairs he will be talking click his head and he will fall. Then click the computer screen (downstairs) until he gets up and moves, he'll lean against the wall. once the guy has got in the lift (upstairs) click on the picture and they guy will get up and fall and die. Once the lift arrives downstairs they guy leaning against the wall will fall in and click the string of the lift, the lift will fall and they will both die. Then click the light above the two guys talking and it will fall on them and kill them. :)