it('should disappear when click mask', function() {
   example = new Alert({
     content: 'foobar',
     hideOnClickMask: true
   });
   example.show();
   mask.element.click();
   expect($('.ui-dialog').length).to.be(0);
 });
 it('should not disappear when click mask', function() {
   example = new Alert({
     content: 'foobar'
   });
   example.show();
   mask.element.click();
   expect($('.ui-dialog').length).to.be(1);
   //expect(example.element.is(':visible')).to.be(false);
 });