GitHub

MooDialog is a MooTools plugin to replace the native alert(), confirm() and promt() javascript functions by more stylish ones. You can use it also for other DOM elements ...

First you have to include the javascript files and css file in the head of your html document. MooDialog does not style any element with JavaScript, but only uses CSS. The Element.setStyle method is ...
GitHub

JavaScript calls in SEB on Mac do not return proper values for confirm dialog windows

When a JavaScript confirm dialog is generated by a web page, it will give two options, "Cancel" or "OK". If Cancel is clicked, the function returns false. If OK is clicked, the function returns true.