Customizing Installation Screens

Hi Friends,

I'm creating a MSI Setup package wherein I need to customize the Installation screens. I have also to check whether certain files exist on client's machine before the Installation completes or else abort the Installation. I found out that one can use the INSTALLER class to customize the Installation(One has to override the Installer class in a derived class)...but I'm not able to use it properly in my Setup Project app. Basically, I can't understand how to pass value to stateServer parameter of the Install() method. I tried but I'm getting errors....I'm quite new to this concept of using Installer class to override the default Installation....Can someone help???

Thanks,
Debsoft