How to increase number of connections to 7.2.1

I need to increase the number of connections to PostgreSQL 7.2.1.

I have tried changing the value of max_connections in Postgresql.conf. It
was commented out (as are all other entries except "tcpip_socket = true").
Setting it to any other value that the default 32 resulted in the server
failing to restart.

I know we should upgrade from 7.2.1 and that is going to happen soon, but
this is a production server and I need a solution sooner.

Thanks in advance,
Edwin New
Analyst Programmer
Toll - Integrated Business Systems
43 - 63 Princes Highway,
Doveton, VIC. 3175
Ph: 03 8710 0858
Fax: 03 9793 3970
Mobile: 0417 341 074
Email: edwin_new(at)toll(dot)com(dot)au