custom text on homepage only - template customization

[streetsweeper]

Hi,

I have an area in my header template that I want certain text to appear only when on the homepage - when visitors go to a thread the thread title will appear in that area instead. I figured out how to pull in the thread title ($threadinfo[title]) but can someone tell me how to write an "if/then" statement that will pull my alternate text in on the homepage?

Thanks!