Whether Time can be reduced for Login?

I am thinking of reducing the time of login in web-domain.
My plan goes like this:

• While entering the username, the onkeyup event will be generated and will check the database for that username using AJAX.
  
• It will yield that username is found and if the correct password is entered, it will check only for the password taken in the variable.
  
• So, will the login time be reduced?

via Yash