Making a database in flash

Hi! Im from the Philippines and I’m a 3rd year computer science student and one of my requirements for the school semester is to build a database for a client. My client is a huge public hospital that needs a database for storing their patient’s master chart in the dermatology department (outpatient-opd and phototherapy unit) because untill now it still uses papers to catalogue records. I chose flash for the interface and php to create and edit the xml documents. Ill be using xml as my storage so flash can directly read the xml documents becuase of the built in methods in flash. The problem is that i don’t know if this is realistic considering the number of records for my client and flash/php is not usually use for creating huge databases. I’m new at this concept but it would be a good system if im gonna use flash/php becuase flash can be displayed in a browser or it could be embedded in java/vb and act as a desktop application and this is also platform independent (flash embedded in java). The reason that im pushing for this idea is beacuase this is only a one time project and i just want to make the system flexible so even in the future the client decided to change their current os or make the service available online for their patients the program is capable of doing that.

this is the link for the interface (not yet complete).