equalize different degrees

i really need help ![alt text][1] i have 2 object, I want object2 to look in the same direction as object1 by changing the degree value of object2, when degree of object1 is 270 then degree value of object2 changing to 0, so on when the degree of object1 is 45 then the degree value of object2 changes to 225, how can i do that ??? [1]: /storage/temp/128880-untitled-1.png