Your description of the model does not match the screenshot I included in my previous post. Specifically, the button should contain an ancestor reference of the view, added to the button via the context menu (right-click) - note its blue frame signifying it is an ancestor reference.
Ancestor references are the method by which data is read from display elements. See the Use a Display Data Element (to retrieve user input) section in stage 3 of the tutorial for more details on ancestor references.
Regarding alternatives to an alert, as I mentioned in my previous post there are alternatives such as popups, dialogs etc. These however demand some additional modeling. Note that popus and dialogs are essentially the same except that one uses a separate browser window, whereas the other is overlayed on the current window. Popups are used in the tutorial beginning with stage 2, with a demo of passing data to a popup demonstrated in stage 13.
You can find additional tutorials here, and demo application models which you can download and study can be found here.
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