Using Model Dialog Boxes
You should avoid using browser native alert boxes, using the JavaScript alert() or confirm() function calls.
These block JavaScript from executing until the dialog is closed. You can use the provided third-party library called Bootbox. This creates a HTML-based alert or confirmation popup. You can also overwrite the browser default alert() function with the Bootbox.alert() method to automatically benefit from it.
An example of how to use the Bootbox alert and confirmation pop-ups can be seen in the hello-world-example,
Modal Dialog Example view:
<installdir>\examples\insight\developer_guide\javascript_api\hello_world_example