Disabling submit button until all fields have values

var fields = “#user_input, #pass_input, #v_pass_input, #email”;

$(fields).on(‘change’, function() {
if (allFilled()) {
$(‘#register’).removeAttr(‘disabled’);
} else {
$(‘#register’).attr(‘disabled’, ‘disabled’);
}
});

function allFilled() {
var filled = true;
$(fields).each(function() {
if ($(this).val() == ”) {
filled = false;
}
});
return filled;
}

Reference:https://jsfiddle.net/chriscrowley/6fdxLkq0/