Java Heap space problem

Hi,

I have an web application which throws out of memory error when more than 5 users logs in .I am using jboss server with linux box.I have 1Gb physical memory. I tried changing the jvm options but still it's not working .I am using lots of session variables.does this costs any real performance issue? please give your valuable inputs

thanks in advance

Sree

[385 byte] By [harisreea] at [2007-11-27 9:08:23]