Excel 2007: modified drop down list, can entries already entered be updated automatically?

Hello,

I have a couple of questions regarding drop down lists via the Data Validation process.

I am using two workbooks. The first workbook has the source data. The second workbook had a drop down referring to the source data in the first workbook.

My drop down selection is a list of cities of the world. I select the city 'Tokio'. The correct spelling is 'Tokyo' but it was not spelled correctly or was mistyped in the source data workbook.

Someone notices the spelling error and corrects it to 'Tokyo' in the source file.

How do I update the already selected 'Tokio' in the second workbook? Is it a manual process where the now corrected 'Tokyo' has to be reselected from the drop down list or can the change be automatic (dynamic)?

Also, I'm finding the source document needs to be open to have a selection available in the drop down cell of the second document. Can the drop down selection be available when the first workbook is not open?

Cheers and thanks,

TV