Ok, You did not include that information in the original post. It is certainly possible to use the update on a manually created form, however, it requires that you have an understanding of how the update process works.
with an update page, you would always have a results page so that you can select the record you wish to update.
The results page will pass the records ID as a querystring variable, for example:
on the update page, you need to create the recordset and set it to filter the ID column using the ID recordset.
you can then bind the initial value for the form elements to the columns from the recordset.