LostFocus method of a text box getting executed before Form_Unload

I am currently programming in MS Access VBA. I have a form with a textbox on it. I am executing some code on LostFocus event of the textbox.

However, when I close the form using mouse and by clicking on close button on right-top corner of the form, with cursor in the text box, I have noticed that LostFocus event is getting executed before Form_Unload event.

Is there a way to avoid this?

Also, where can I find priorities of the events?? Or How are priorities decided in VBA?

EDIT:

My exact application is like this. I have a form in MS Access which is used for accepting users' login credentials.

I want to disble textbox for Password and Login button till a valid Username is entered. I check if the username is valid or not on onLostFocus event. Now, consider a case where this form is closed without entering anything in Username textbox. In that case, onLostFocus event gets executed before Form_Unload event.

However, for normal operation, I require onLostFocus event because, on that event I enable Password textbox and login button.

Could there be a different way of doing it??

"I check if the username is valid or not on onLostFocus event."

Do your validation in the after update event of the username text box ... enable/disable the password text box as appropriate when the username value changes.

You can initially disable the the password text box at form load, assuming the form loads with the username text box empty.