Login Form and UX

Hello Webix Team!

We need a login form with the following UX behaviour:

Two simple input fields: 1. email and 2. password

When user enteres his email thae first field is validated. If the format is not a correct email an error message is shown below the email field and the focus stays in that email field!

When user enters a valid email and presses tab, then focus moves to the second field, the password field. No error is shown yet, althoug the password field is still empty.

Once the user enteres at least one character the login button becomes active.

When user deletes all characters from password field an error message is shown for that field and login button is disabled. Until user enteres at least one character for password again.

I am already close but not yet there:
https://webix.com/snippet/af32feda

Biggest problem right now: When Webix shows error messages below fields, then these fields loose their focus.