SQL Injection Fix

We are looking for someone to secure our backend control panel from SQL injection. Our system is built using PHP and OOP. Please only bid if you have extensive knowledge in PHP and OOP. We will have more jobs available once the first job is complete. This project is only for securing the script from SQL injection. If you complete the job to satisfaction, we would rehire you to complete the following job. Create a user/order registration form that ties in with our database. The registration form would create a new user account and set the account to inactive, it would than need to add a sub-domain and copy our API files to the sub-domain "public_html" directory (doing all of this in the background). After the customer has completed the order form, they will be redirected to paypal where they can pay for our service. After payment is successful, the user needs to be redirected to our website where their account will be set to active and than they will be able to login to their account. The database is already built so it would be a matter of creating a form and sql queries to post the information to the database. You would however need to code a script that will create the sub-domain and copy the /api/ files to the sub-domain directory. You would also need to create a script that handles the paypal redirects that activate the account after payment. Please only bid on this project if you're capable of doing both projects as I would prefer to work with one individual. We plan on adding many new features to our script, and are looking for someone with extensive knowledge of PHP and OOP as stated in the top of the project description. We are ready to get started!