I have attempt to open Help dialog after click the Help icon.
At first, I’ve use Yii widget for creating the dialog and compose the Jquery script for the Help icon clicked, to open dialog. I notice that all other Jquery script is working fine, except this. For investigating what happen, I use Jquery UI dialog method the create the dialog
Sometimes the widget that you display in the dialog, overrides the dialog’s own scripts and then the dialog will not work and you get errors such as ‘dialog is not a function’.
One way of dealing with it is to ensure that the correct files are loaded - as georgebuckingham explained.
Another way is to insert an iframe between the dialog and the widget in the dialog. Iframes are treated by the browser as a separate page with its own scripts. So the scripts of the widget on top of the iframe, will be separate from the scripts of the dialog under the iframe. Check this wiki.