i am trying to use the modal directive from ui-bootstrap 0.6
here is the working default plunker from the ui-bootstrap page:
http://plnkr.co/edit/JGBiBSeRqO
You can use quotes as the other answer suggests, or you can also do as the example in the docs and define the variable:
var ModalInstanceCtrl = function ($scope, $modalInstance, items) { ... }