[syslog-ng]syslog-ng sighup problem

Hi , I want to know how should I re-read my syslog-ng configuration file without restarting syslog-ng. I found out solution by sending sighup signal to syslog-ng but its not re-reading it i.e when I give kill command with sighup signal to syslog-ng pid it does nothing what is the problem or any other solution. With regards, Jayesh shah