Lets see what you have. Ideally would like to have end user book a show for a certain date and time, pay for and print out a barcoded ticket. System would allow theater to scan in ticket to confirm entry of client to theater. Seat choice would be nice but not necessary, integrated online payment nice but not necessary.
There will definatly be additional contract work on changes/additions to the basic script installed and integration to an existing php/mysql script for the right person with strong php skills.