bottom panel problems

[Miles Sharpe]

Hi All. Thanks for all the help to date. I now have more problems.
My son removed the bottom panel where you see all the desktops but I
have managed toget it back again but now if I minimise something it just
disappears and I don't know where to find it again.
Please can you help me. I am using 9.04 fully upgraded to yesterday.
I am a beginner in Linux and Ubuntu so if I need to enter a terminal
command can you give me the whole command. I have struggled before not
knowing whether or not to use sudo.
Thanks for all the help and a wonderful operating system.
The more I use it the more I regret wasting time with windows.