problem editing table after add

I have a table voters with a detail relationship to voter issues.
I can select a voter in the voter list... click on voterIssues and then add a record for voter issues for this voter... works fine. When I go back to the voter list later and click on the voterIssues, it shows me the record that was previously entered... but when I try to edit this record I get the message below (note all I have done is click on the "edit" link:
PHP error happened
Technical information

Error type 256

Error description Unknown column '' in 'where clause'

URL www.ccdemocrats.com/test/voterIssues_edit.php?editid=

Error file /home/ccdem2/public_html/test/include/dbconnection.php

Error line 26

SQL query select `group`, `voterID`, `issueA`, `issueB`, `issueC`, `issueD`, `issueE`, `issueF` From `voterIssues` where ``=NULL
help?