+
+<script>
+ var $input = $('input:text'),
+ $register = $('#register');
+ $register.attr('disabled', true);
+
+ $input.keyup(function() {
+ var trigger = false;
+ $input.each(function() {
+ if (!$(this).val()) {
+ trigger = true;
+ }
+ });
+ trigger ? $register.attr('disabled', true) : $register.removeAttr('disabled');
+ });
+</script>