Combined if/vlookup formula issues

Hi All,
I need some help from the experts!

Basically what I need is a formula in the Login logout tab in column N that will compare the person listed in A8 with the schedules tab to find out how far off of actual break time they are. In the example I have already listed in the sheet the person was supposed to have break at 6:15 according to the schedules tab but actually took break at 6:10 according to the Login Logout tab. So i need a formula to calculate this even if the data changes to include any one person that is listed in the schedules tab. I have tried combo IF/Vlookup but cant get it working. All trial data is listed in 'actual log in log out' tab so this formula would have to work for each person in this list. Any help would be amazing!!