Can't use the net

I have just installed Linux and I am unable to surf the net. I have done exactly how PC Quest has said in its reviews about Net Configuration. I am successfully able to dial and connect (looks like). The on writing a URL address on the address bar of netscape,The modems RD and SD lights blink for a while and the Network status shows that some bytes have been sent and recvd But finally, it says unable to open site www.vsnl.com or for that matter any other site. I also configured Messenger foir the purpose and that also says the same cannot find pop.softhom.net. Moreover is ti possible to edit the dial-up script of wvdial as w have in widows..... thats for the Mantra Account where you need to send an <Enter> before all the authentication starts.