What you have to do is emulate/implement the Page Up/Down functionality yourself.
That is, you emulate Page Up/Down. For each page you want to jump to, you can do the following:
1. Create a button for each page in a hidden page in the activity. These buttons contain nothing but page jumps.
2. When the activity starts, retrieve these "jump" widgets and add them to an array.
3. Create an index variable (at activity level) that points to current page you are on. For example, assume your starting page is first in the array (that is, the jump button reference in array should be at index 0).
4. In the Activity Hard Button properties, your ProntoScript that you could for Page Up/Down should simply increase or decrease the index such that you treat your array as a circular buffer. After increasing/decreasing the index, you simply dereference (retrieve widget at) the current array element and then use scheduleAfter() to execute the action as mentioned above.
If all pages are in the current activity, then this will work as your activity script will not be interrupted.
However, if a page you want is outside the activity, then you could, in theory, use System.setGlobal()/getGlobal() to save/restore the current index once you have jumped 'Back' from the page outside the current activity. The only caveat to this approach is that any connection (TCP/IP, for example) that you have made will have to be restored upon reentry. Otherwise, if you just want to emulate the page up/down functionality, this should work just fine.
Early in ProntoScript Beta, Philips had a config file that did many things such as this. They have released bits and pieces of this config as other modules. However, as this configuration contained some functionality that proved unstable to Javascript, it was never released. The type of functionality I'm describing here is, for the most part like functionality of jumping between macro and device side of remote for classic prontos. Once implemented, you can "remember" the last page of the device that was currently viewed.
