[SR-Users] regular expression question

[Satish Patel]

I am trying to block SIP scanner so i am trying to use following logic
only allow "My-UserAgent" and block rest but its throwing error, but
if i use  =~ regular expression which works! why negative match
doesn't work?

if($ua !~ "(My-UserAgent") {
                   xlog("L_INFO","On more scriptkiddie, coming from
$si, blocking");
                   exit;
                }


what could be wrong here?