There is a system of knowledge control with the help of tests. Works on php, mysql through the browser. When the user selects the number of questions, the subject of testing is that testing the form on this page begins. The problem is that when testing is going on and the user is not sure about knowing the answers to the question, he can reload the page and he will download new tests from the database. How can I avoid rebooting and opening the test for 1 user 1 time?