Validate `<input>` on tab over?
However they all seem to be constantly validating, which could prove annoying to end-users.
Can I make it validate only after you've tabbed to the next <input>,<button> or <a>?
[using pure JS, no JQuery or other library]
Sure. You'd want to use the onblur event on your element.
elem.addEventListener('blur', validateInput, false); // validateInput being your validation function