update table data from form help

[Darkmatter5]

Say I have 2 text boxes FirstName and LastName with a submit button and a particular user's last name changes, how can I submit the change?  I only want to change elements of the table that have data in the text box.  So change only LastName, but still have the ability in future instances to also change FirstName.  Basically if a text box is empty don't include that element in the table update.

 

Clear as mud?

Thanks in advance!