1 x 1 Meeting System

We are interested in creating a meeting system for an upcoming conference that we will utilize in our site. We have 3 types of users for this system, Attendee users, Company users, and an Admin user. Our site currently has an authentication system that we will use so there will be no authentication involved. The objective is to facilitate meetings between attendees of the conference and the presenters of the companies who can answer their questions. An Attendee will log in and be able to see all the companies presenting on the list. They can choose one and choose a meeting time. This timeslot would become "Waiting for approval" and send an email to the company user they have chosen. The company would log in and approve this time or offer a different time. If approved the Attendee gets an email that says "your meeting tues at 3pm with Company1 is approved" and when they log in again the timeslot says "Approved". If the company denies the time, maybe the company can also send a note that would be part of the email the user will get (eg. The Company cannot make the timeslot, but they sent the following note "How about Tuesday at 3pm?"). Also a user making a meeting cannot make more than one meeting at Tues 3pm, the system will tell them there is a schedule conflict. The company users will be allowed to make meetings with other companies as well as view the schedule and block out times that are unavailable. I think this should work fine since currently each "room" has its own timeslots and availability, so if we change "room" to "company" they can use this function. Both Attendees and Companies should be able to remove meetings, maybe also send a note when they do, in case their schedules change. The Admin user will be able to see all the companies and investors and the times for each. Maybe there should be a config file that will allow us to be able to choose time increments - 30mins / 1hr / 15mins etc This script needs to work in all browsers? This is important as well