external hard drive, music and itunes?

This is my first post and only had my macbook pro since yesterday so my question may turn out to be a bit silly, its however no less frustrating.
The problem i am having is that all my music has always been stored on an external hard drive, therefore saving disk space on my laptop.
I had hoped to continue this way of working on my mac but when i open any songs from my external drive in itunes it seems to automatically transfer them onto my macs hard drive.

If anyone is still following, do you know if there's anyway for the music to be loaded onto my itunes library but the files to stay firmly on the external drive?
I have a serious amount of music and bought only the 160gb MBP since as i say, i keep everything external.

Many thanks for any advice

First, plug in your external drive. Then, under the iTunes menu, choose Preferences>Advanced and change your iTunes Music folder location to your external drive.

nice one dude, thanks for the quick reply
Back to square 1 putting my music on but at least it will be done right,

Thanks again =]