is there any way we can set the focus to the validation summary if there is any validation error when click on submit button ?
i got a long form, so users might not aware of the validation error message which will display on top of the form.
I am not sure if you can set the focus to the validation summary but maybe this tip is also helpful to you. It seems to have helped a couple of people: tip: how to move validation error messages from top of page
Also: Nintex released its new responsive forms designer in Office 365 and is going to release it to 2013 and 2016 too by the end of the month (see the last comment here: Can I download the new verion of Nintex Forms known as "zinc" )
That designer will switch validation in a modern way and errors are shown directly below the field like here (sorry it's in German though):
So maybe this is an option too?