When I install Ubuntu I tick mark 'auto-login'. So I did not need to enter password everytime when machine start. Now I have an another user in my machine. She take sit infront of my computer everyday for 1-2 hours. So I create a new account for her. In this moment I need to disable 'auto-login' at startup.
When account was created then their is an option which need to mark as passwordbased login or passwordless login. My first account password requirement is disabled. Now do the step by step doings below.
Go directly to System > Administration > Login Screen
You must enter password to unlock it before everything. Now check carefully whether anyone have permission to 'Auto login'. It might wrote as
Log in as (User name) automaticallyClear tickmark from it. Click to tick on the second option. Which is said:
Show the screen for choosing who will log in