passing a variable to another page

[Mo]

On one webpage I have a datagrid which is filled when the user selects some
search criteria (e.g. surname or DoB) in different text fields and clicks on
a button control.

The datagrid also contains a 'button column' which the user can use to edit
and save changes to individual records to the db. The contents of the
datgrid look like this:

PatID Surname Forename DoB Initials etc etc
DER123 SMITH JEAN 02/02/1945 L

Everything works fine so far.

However, I also want users to be able to add records to a related table
(which is at the many end of a relationship) based on the record they've
selected from the datagrid. I've set up a 'hyperlink column' in the same
datagrid which redirects them to another page where they'll be able to add
data and save it.

The problem is of course, how do I access the contents of a cell (PatID) in
the datagrid and pass it as a parameter to the second page when the user
clicks on the hyperlink column? This is required because the patid will form
the foreign key of the table at the many end of the relationship.

I hope I've made myself clear. Please let me know if you need additional
information.

TIA for any help.

Mo