Setting the value of the text fields on this url works oddly. Move the mouse over the highighted dates in the calendar. The text field seems to get the new text added. You can tell because the scrollbars resize and selecting where you expect the text to be exposes it. But it shows up in white, same color as the background. Haven't looked into cause. Could even be a style thing.
*** This bug has been marked as a duplicate of 2629 ***
The text is being updated. Update the field by moving the mouse over one of the numbered dates. Then sneak your mouse into the field and hilight the text. It's correct, just not showing up because it's white text on a white background.
Verified Dup of Bug 2629