Need easy to modify variable for Google Spreadsheet key

[dhornbein]

Call for the Google Spreadsheet json data appears in the index.html file.

<script src="http://spreadsheets.google.com/feeds/list/0AspZRjIECCvPdGE0S3NIRzR0OW4ycDFVeU0wWmhDM1E/1/public/values?alt=json-in-script&amp;callback=phenClockGDImport"></script>

The script takes one variable, the key: 0AspZRjIECCvPdGE0S3NIRzR0OW4ycDFVeU0wWmhDM1E

Seen here in the Google Drive link:
https://docs.google.com/spreadsheet/ccc?key=0AspZRjIECCvPdGE0S3NIRzR0OW4ycDFVeU0wWmhDM1E

There should be a simple method for setting this variable.

Ideas

The easy way

Set a js var at the top of the page with the key:

var gdKey = 'AspZRjIECCvPdGE0S3NIRzR0OW4ycDFVeU0wWmhDM1E"

The better way

Have a input text field on the page which accepts the key and set's the GET variable so that the key can also be set via the URL. Input to the text box should accept both the key alone or the google doc link in full.

[thiagodemellobueno]

Said input box should pop a modal, know any simple vanilla js modals?
This should be easy enough.

But just having a key isn't enough right? the gdoc needs to be published/shared in some specific ways?