set custom message in html5 required field validation

[Bakuda]

i have one form with many input fields. i have put html5 validations\[code\]<input type="text" name="topicName" id="topicName" required />\[/code\]when i submit the form without filling this textbox it shows default message like\[code\]"Please fill out this field"\[/code\]can anyone please help me to edit this message?i have a javascript code to edit it but its not working\[code\]$(document).ready(function() { var elements = document.getElementsByName("topicName"); for (var i = 0; i < elements.length; i++) { elements.oninvalid = function(e) { e.target.setCustomValidity(""); if (!e.target.validity.valid) { e.target.setCustomValidity("Please enter Room Topic Title"); } }; elements.oninput = function(e) { e.target.setCustomValidity(""); }; }})\[/code\]