php/mysql web form work

i have a web form that needs to be modified. Add additional input fields on web formmodify routine in mysql table read existing data (edit record) parse input characters on the fly to prevent errors (replace ampersand and slash with ascii) fix paypal field to accept html for input form should work if record is added or updated form already exists and works, just needs to be expanded with a few more fields. fields already exist in the products table. must know how to work with mysql routines and xml project budget $40 delivery time frame required is 24 hours or less