Identify An ID Number And A Password

I need to identify an ID number and a password. Like this,(Form1) there's a two textboxes, one is the ID number and the second one is the Password, when I enter the two it means i Log-in, the system needs to identify if the ID number and the password is registered in mySQL, then if it is registered a message box will appear "You are log-on" and a form will show (form2) in 10 to 15 seconds that is having the information of the student, then it will automatically close then it will go back to the form1 which the another user will log-in again.

(this is Form1 too) then here is my second problem, like what i said in the first problem, the program needs to identify that the student is already log-on the school and he is going to log-out, (like this, system is going to identify that the id number and the password is already declared on the first form, so it will be the log-out code, then a message box will appear "You are Log-out".

(Form3) then here is my third problem, i need to identify how many people is inside the campus and not going out on the campus. The person or student that is not logging-out on the program or the system will be count when i click the Button 'Count' and the number of student inside the campus will be display in a 'Label'(it will be inserted also or having record on mySQL tableInside).

('Form4') then my fourth problem is the system needs to identify how many students did log-in on the campus. Or the system will identify how many person input their ID Number and Password on the first form ('Form1', it will be inserted or having record on mySQL tableLog).