adding to an array

Hello , I need a way to read the following text file and add to or delete from or change the data. I have been able to move it all into an array using this code $groups= file("group"); for ($i=0; $i<$number_in_group; $i++){ } But I can not figure out how to search the array and delete from or add to the array at a given point. I would like to say add another user to the end of site6 or delete a user from site3. Could sombody give me a hand here. I have read the manual for arrays and still can't figure it out. site1:x:503:tester1 site2:x:504:tester2,tester2a site3:x:505:tester3,tester3a,tester3b site4:x:506:tester4 site5:x:507:tester5,tester5a,tester5b site6:x:508:tester6 site7:x:509:tester7,tester7a,tester7b -- Best regards, rdkurth mailto:rdkurth@starband.net