Software Deployment

I'm trying to do a silent install of WebEx Meeting Manager but can't get past a "Browser List" window that pops up. I extracted the installation and created a setup.iss file using the -r switch. When I run the install, I get a "Browser List" window that tells me: "WebEx Meeting Manager will be installed in the plug-in folder of tjhe browsers listed below." OK is the only option, then the install completes successfully. Anyone have a public property I can add to the command line to get past this window?