Database design

I am creating a database for a web application. The idea for the application is for a company administrator to be able to log into the site and allocate staff to a project which will be a clinical trial at a particular practice. Staff will be able to log in and update the status of the project they are working on and clients will be able to log in and book a member of staff. Administrators will be able to add / edit / delete - staff / clients / clinical trials.

Here is my database diagram:

http://www.mania.plus.com

My problem is each different clinical trail will need to have different data collected for it. How could I handle this in the database model? The administrator would like to be able to edit the data collected for each trial via the site...

Any other comments on my database model would be appreciated as this is my weakest area of web development by far! Received on Mon Mar 10 2003 - 14:51:21 CET