Try this
HTML
<input type="text" name="" id="voornaam" value="" class="full" />
<input type="text" name="" id="achternaam" value="" class="full" />
<span class="data-name">Dhr. name lastname</span>
jQuery
$('#voornaam').on('keyup', function () {
var name = this.value;
var lastname = $('#achternaam').val();
$('.data-name').text(name + " " + lastname);
});
$('#achternaam').on('keyup', function () {
var lastname = this.value;
var name = $('#voornaam').val();
$('.data-name').text(name + " " + lastname);
});
solved filling a form with jquery [closed]