Hello Reader! If you have been working with HTML 5 validation then on incorrect email address web broser will show the default error message "please enter a valid email address". Now you can make it custom and write your own message. Lets see the code below:-

Then HTML form is as same:-

<form id="myform">
    <input id="email" oninvalid="InvalidMsg(this);" name="email" oninput="InvalidMsg(this);"  type="email" required="required" />
    <input type="submit" />
</form> 

Now in the JS code :-

function InvalidMsg(textbox) {

    if (textbox.value == '') {
        textbox.setCustomValidity('Required email address');
    }
    else if(textbox.validity.typeMismatch){
        textbox.setCustomValidity('please enter a valid email address'); //write your custom code here
    }
    else {
        textbox.setCustomValidity('');
    }
    return true;
}

As you can now put your own custom message on 'text.setCustomValidity'

Source By :- jsfiddle.net