[otrs] how to make index.pl as default page

I have my site running on some thing like: http:localhost:8081/otrs/index.pl what i need is tht typing just http:localhost:8081/otrs/ should go to index.pl (by default)..... I have Apache 1.3, Win2k and i have already tried adding index.pl in <directoryindex> entry of httpd.conf.... any help is greatly appriciated Regards Imran