JQuery :: Attaching Validation Plugin Callback To Modal Form Button

I am trying to use the jquery validation plugin with a modal form. When I click the 'Make a booking' button shown below there is no response. I guess there's something about the dom I am missing, which tends to be the case quite often.

$('body').click(function(event) {
if ($(event.target).is('a.add')) {
event.preventDefault();
$( '#dialog-add' )
.dialog( 'open' );
}});
$( "#dialog-add" ).dialog({
autoOpen: false,
height: 340,
width: 400, .....
draggable: false,
position: "center",
resizable: false,
modal: true,
buttons: {
"Make a booking": function() {
$('#addbooking').validate({
submitHandler: function(form) {

//ajax
});
$( this ).dialog( "close" );
}});},
Cancel: function() {
$( this ).dialog( "close" );
}},
close: function() {
}});