2 questions- on SharePoint online (Office365-E3).
I want to create some business form.
My user wants some validation rules, which will do validate value before submit happens to list/library .
Like...if users has Total limit of 300 Dollar,
So user1, submits 200 dollar in 1st time, but ,
say..he is again submitting for 200 dollar (which he shouldn't) in 2nd time,
So,can he be validated for the value on list items that his total (200+200=400 exceeds allowed value of 300) ?
2nd- which is correct approach for doing this-Infopath or by developing Apps.