How to create a custom window pop up when chekcbox is clicked or unchecked?

I have create the pop window when user click check-box. When the check box is clicked, I display the pop up with relevant message for user to confirm if the really want to click the check box. Same when the check box is checked and user want to uncheck it. I want to display the pop up with relevant message if the really want to uncheck the checkbox.

In few steps this what suppose to happen

1. If user clicks the checkbox, i want to show my custom pop up to ask user if they really want to check it. If user click YES, I check the checkbox. Else if they click CANCEL keep checkbox unchecked.
2. If user want to uncheck the checkbox, I want to also show my custom pop up to ask user if they really want to uncheck the checkbox. If they click YES uncheck the checkbox. Else if they click CANCEL keep checkbox checked.

Here is my CODE

Sorry if this is a duplicate of asked question.