emailing from browser spreadsheet

When I open a web browser (IE 6.0) Excel xls page, then enter some numbers
into cells, then send the spreadsheet by email, the newly-added numbers are
not in the spreadsheet that's received by the email recipient. When I do the
same thing with a hard-drive-based spreadsheet, the newly-added numbers are
in the spreadsheet that's received by the email recipient.

Why aren't the numbers present in the emailed web-based spreadsheet? Is
there a way to get them to be included?

Thanks,

Mick Ruthven