Set custom HTML5 validation messages on elements and reset after user input

gistfile1.txt

/** ============  SET HTML5 VALIDATION MESSAGE ============ 

document.getElementById('element').setValidationMessage('Oops.. that\'s not right');

=========================================================== **/

(function(window, Element){
    "use strict";
    
    Element.prototype.setValidationMessage = function(msg) {
        this.setCustomValidity(msg);
        function removeCustomValidity(){
            this.setCustomValidity('');
            this.removeEventListener('input', removeCustomValidity, false);
        }
        this.addEventListener('input', removeCustomValidity.bind(this), false);
    }
    
}(window, Element));