iTunes album artwork

I have some songs which i have tagged, with the tag of my site. When i open 7 songs only 3 artwork covers coem up. Why dont all 7 coem up?
Answer #1
try selecting all the songs, right clicking, choose ‘get info’, then say ‘yes for editing multiple items’, go and copy the image you’re going to use for the album art, and paste it into the box that came up in itunes
Answer #2
try selecting all the songs, right clicking, choose 'get info', then say 'yes for editing multiple items', go and copy the image you're going to use for the album art, and paste it into the box that came up in itunes
Exactly!
If it still do not show covers for all songs, delete them from iTunes library and import them again, so that iTunes can read all data and tags (and covers)
Answer #3
basically all the song have the same site, i think thats why all the song come under the same album. Is there anyway to seperate them?