In Layout Mode, select Set Tab Order from the Layout menu.
oh my I have messed with my post, sorry Mr. Phill I tried to rate best answer your reply but instead it gone under my reply and when I tried to delete my reply incidently your reply got deleted.
You'll need to use the mouse or a script to move the next tab panel to the front. You can use the Name box on the inspector's position tab to give each panel an object name. (Click th tab once to select the entire control, then click again to select just one tab panel, then use the inspector to gvie it an name.)
Then the script step:
Go to Object ["Panel name in quotes here"]
Can bring up the next tab panel. An OnObjectExit scrip trigger on the last field in the preceding tab panel can perform this script or you can set up something more sophisticated using the OnObjectKeyStroke trigger and testing to see if the last character entered was tab, return or Enter and thus it's time to move the focus to the next field in the next tab panel.