Deleting songs from library, iTunes
 

Hello :)
I just have one question about this limewire deal. Okay, so I download songs from limewire and put them into my iTunes library. I am wondering why I can not erase the files from the limewire library since they are already in my iTunes library. Everytime I try to erase a song off of the limewire library and then I try to play that same song on iTunes it says that the file can not be found. Is there any way to erase from limewire without messing up iTunes?? Thanks for any help.
Alicia