installation issue - please help

This is probably a simple issue to fix, but I have just recently acquired my first Mac (macbook with leopard) and wanted to play Warcraft 3, but I can't seem to install the game. I get the following messag, after entering the CD key:

Iinstallation failed,

Couldn't create destination folder "warcraft III". You do not have permission to add files here. Pleas try installing to a different location.

Please advise

Welcome!

See if this will will help.
http://docs.info.apple.com/article.html?path=Mac/10.4/en/mh669.html

Thank you for your help, but my problem hasn't been resolved because of a few issues...

It states under my profile that I can only read the HD; so I 'unlocked' the HD and was prompted to enter the admins username and password (I thought my account was the admin?) and it said that it was incorrect. I was surprised as I only have one profile and thought it would automatically be the Admin?

Anyway I checked the help and was advised to put in my install disk and hold down C to change the admin password. I was asked for my new password and password help, then it tells me something along the lines of "you cannot change the password or there was an error"

Please advise or let me know if I need to post this in another part of the forum.

If you updated recently, this maybe the problem.
http://docs.info.apple.com/article.html?artnum=306876

Yes that was the issue! W3 is now installing.

Thanks for all your help