Coding a smart web application in PHP and MySQL

The web application should be coded in PHP. PHP code must be clean and readable. SAFE coding is required to prevent any type of code injection. The frontend should be designed professionally in HTML, CSS and PNG. It shows a free product (downloadable eBook) which user can download after filling out mandatory fields. User can select between seven languages. Language information are stored in a XML file. Information will be displayed on the frontend in his selected language. The web application will count the number of downloads, will measure the success and will display the success in a professional manner. In the backend the information about the eBook such as image, file, link, data should be manageable through an admin or an authorised user. Log In mask should be available. Data are stored in mySQL and should be encrypted. Decryption should be possible, if Data is required for processing. An easy user administration is required to create new users, delete them, assign login facilities, etc.