anti virus, skype and more

hi there
i am a mac new user. i have several problams:
1. I think i got a trojan horse. when ever i try to go to my home page, a different page pumps up, which is an add for spywares suprisingly or not.. is there a good anti virus software i can find?
2. skype doesnt seem to function very good. when ever i try to chat it doesnt show the msg though it shows mistirious scripts instead. any ideas how to solve it??

thanxs for your help

Cant help you with Skype, but if you have a DNS trojan then ClamX can help

ClamXav

or have a look at this article

First Look: Trojan Horse warning: What you need to know | Utilities | Macworld