I have located it in the manual as advised. Thanks for that.
This forum has been my first port of call if i encounter problems and i always appreciate all the help i have gotten from this forum.

I have another problem on the archive logs. From Spotlight on Oracle i notice that the archiver is no longer archiving and on mouse over to the archive log bucket it displays "No more room for archiving logs". Pls can someone give me an idea what has gone wrong. There is space on the system to take more archive logs.