well... my friend hit my laptop screen from the back after that it does start but it fizzes up with black lines, multi colour!

You might get lucky and a shop might find a loose connection in your system. Getting a replacement screen off ebay might also be possible. I would get the whole assembly. You can also look for an identical used laptop on ebay and transfer your old hardrive over to the other laptop.
 
If only the screen went bad, then an external monitor could be used until it gets fixed.