Please Help Me, Please!

I have made a game and now all i need to do is add boundries to it but every time i try i stuff up, plz cood som1 help me???¿¿¿

i have got an object called spaceship and i want it 2 stop when i hit an object called blok(stop so i cant go up but i can still go down) plz elp me and if there is som1 great full enough cood u maybee even mka e a script for me which in cludes the above and movment(left rith up down) so i dont stuff up d script trying to put in the boundries bit!! so if any1 understands plz help me

i hve attached a sample file that u cood add script 2

(FLASH 5 prefered )