PHP - Validation and other for HTML form

Hi, I am working on a project which requires an HTML form to populate a MySQL database(table within) which I have already designed and tested for which I have a [login to view URL] file in place. I need the following functionality: • Form validation •Thankyou message on form completion •Auto e-mail welcome message/username/password •From a form field (invite a friend) send an e-mail with automated message inviting friend to join the site • Any other functionality you might think necessary for a secure form I would be obliged if this work could be completed by 9am GMT 20th April or sooner if possible. There are only 11 fields on the form so it might be possible for me to duplicate the areas if you 'commented' which code required to be duplicated so I could do that myself and keep costs down. Many thanks