<!--#if expr="$REMOTE_ADDR = /^128.235./" -->
                        welcome njit user
			<!--#include file="njit.inc" -->
        <!--#else -->
			welcome non-njit user
			<!--#include file="non-njit.inc" -->
        <!--#endif -->

the command to make the file executable and enable server side include is:
chmod a+x ssi.html