131477 backend site:accouts, booking

hi,. i have a site made already. but i require some sort of booking system put into the backend, which will involve some simple calcualtions. i have the docuement ready for u to look at. deadline: 2-3 weeks max. future work is available. u need to be able to talk via msn also..and email/gmail chat etc.. u need to be able to start the project now. payment on completion.