Can anyone help me with this posting error?

Undefined constant "threadid" on line 15 in /home/eforum/public_html/newthread.php(309) : eval()'d code
#0 /home/eforum/public_html/newthread.php(309): eval()
#1 {main}


Fatal error: Undefined constant "threadid" on line 15 in /home/eforum/public_html/newthread.php(309) : eval()'d code in /home/eforum/public_html/vb/vb.php on line 287