Restrict access to the exam

Hi community, 

I have created an exam that includes four slides: 

• a title slide
• an instruction slide with an acknowkledgement box
• a question bank of 215 questions 9with a draw of 75)
• a results slide

I have included a Number variable that limits the end user to take the exam twice. Everything is working well, EXCEPT...the LMS (Litmos) has an exit button that is on the screen outside of my exam. When the user selects this, it is not counting that as a try, as a matter of fact it isn't even reading my variable of two trys. So while my course is working properly, the achieved result isn't. Is there a way I can only give the learner access to the course, twice? What sort of variable would I use for this? True/False. I basically want to see if I can lock them out of the course on the third try. Any suggestions welcome.