Multiple To:'s in mail()

Hey, I need to be able to send multiple e-mail's via one form on a website. What I need to have for the user is two selection boxes with multiple e-mail addresses in each, like this: <select name=email1 multiple> <option value=User1 <user1@domain.com>User1</option> <option value=User2 <user2@domain.com>User2</option> <option value=User3 <user3@domain.com>User3</option> <option value=User4 <user4@domain.com>User4</option> </select> <select name=email2 multiple> <option value=User1 <user1@domain.com>User1</option> <option value=User2 <user2@domain.com>User2</option> <option value=User3 <user3@domain.com>User3</option> <option value=User4 <user4@domain.com>User4</option> </select> I am not sure how to pass the e-mail addresses to the script. What I need to have is individula e-mails so that the people that have the e-mails sent to the do not know the addresses of the other people that it was sent to. The e-mails need to look like they are all individual e-mails. Is there any way to do this? Do i need some sort of loop or something? Thanks, Jeremy