In ajax.php added and tested testNewTape().  In functions.php adjusted inputs on addTape() so that the default location for a new tape is only set if a location is not passed in.  In main.js added event listener and associated code.  In main.php, no idea what was done there. :)  In addtape.php added code to check the default location and set is as default.  The user can change it but the default is always set in the drop down.

Special thanks to Jared Meeker for help with the Javascript.