Help me!!!!!!! i need help with my computer screen.?

my screen ended up rotating so insted of it being right side up now i have to turn the screen to its side just so i dont get a neck ache just from looking at it side ways. im not sure how it got like that i know my coworker laid a book on top of my keyboard by acident and it hit some keys on the key board and i need to fix this. i cant log on to the control settings to fix it because its a companys computer. does any one know the keys i have to hit to get my screen back to normal. help me please.