Linksys Wrt54g Configuration With Mtnl Utstar Modem

hi everybody,Last week i purchased Linksys broadband router(wrt54g) but i m unable to configure it with my mtnl Utstar modem.Although my pc is detecting the linksys router but while running linksys cd set up its showing the error that internet connection is not found.I tried all possibilities by changing the IP addresses and changing the different connection type of modem and router but no success yet.please anyone help me by sending step by step configuration of router with the mtnl modem.