Hiding or closing js file's dijit/dialog variable when html file's if/else statement is fulfilled

Let me first say that I am new to coding! The bulk of my code was created by combining examples I found on the internet.

I created a splash page for my app. This splash is composed of a content pane within a tab container within a dialog.

My goal is to have a disclaimer on one of the the tabs where a user must accept some terms and conditions before the dialog can be closed. I plan to eventually disable the option for a user to escape/close this dialog.

The tab container, content pane and dialog are handled in a js file. Within this file, I am referencing an html file as the source for the content pane.

The html file is being used for the disclaimer. I've created an if/else statement where the if returns an alert when the user fails to click the "I agree" checkbox prior to hitting the continue button. The else statement would close/hide the dialog if the user has checked the "I agree" checkbox, and would allow them to start using the app.

The problem is that I cannot figure out how to use the else statement to close/hide the dialog in the js file.

I've looked at similar questions here on stack and although I can somewhat make sense of the answers for those particular questions, I can't seem to apply the concepts.

Any help is appreciated!