Create a software for business & sales management

.- System must have different language selection. So example each user selects the language he wants to use. There should be a default language that is used to initial users creation. All the system works the same, the language is only to set of text on labels of users. Need to be developed using Ajax if possible JQuery. Well documented, the database is MySQL. This program is intended for use of our customers who are different non related business. Each customer has its own database or at least work like if he has his own (having one database but identify its records by the ID). Each customer has its own users each of them with its Login/password and permissions in each of the modules and functions of the final system. But a must is that we need to have a simple way to activate or deactivate a whole customer account in case of a demo or simple if our customer didn’t pay us. Look in the attached file for all details.