I have 14 yeras experince in IT field and since last 5.6 years I am working on PHP, MySQL platform.
I had developed many large application during this 5.6 years. I will give you concreate and robust solution for each application. I will always take care of client side and server side validation, as well as URL parameter which are primary target for hacker. For this reason I will always test application in a negative way so my client will get 100% solution.