Ajax contact form return 0

Your javascript is missing an action parameter with the data:

$.post(action, {
        name: $('#name').val(),
        email: $('#email').val(),
        phone: $('#phone').val(),
        subject: $('#subject').val(),
        comments: $('#comments').val(),
        verify: $('#verify').val(),
        action: 'ajaxContacForm' // <-- added action here
    },
    function(data){
        document.getElementById('message').innerHTML = data;
        $('#message').slideDown('slow');
        $('#contactform img.loader').fadeOut('slow',function(){$(this).remove()});
        $('#submit').removeAttr('disabled');
        if(data.match('success') != null) $('#contactform').slideUp('slow');

    }
);