Problem With DVD ROM

i am facing problem with dvd rom.the problem is the tray of the dvd rom opens & closes on its own & this goes on continuing… is ther any solution for this problem..coz i cant even access any cd or dvd or even i cant copy the data fully..when ever i insert cd or dvd it closes & suddenly in between the copyng or installation process it ejects on its own.. if any solutions for this kindly provide it…. thnx in regards