I would bet dollars to doughnuts that Firefox is having trouble with your onfocus event. Try calling the event a different way. I think a pretty standard way would be to include name attributes for your text input and your form and try an unobtrusive function, something like...
document.formName.inputName.value = '';
I wouldn't change much. If it's working in the other browsers, you're really close.
Whatever you can do or dream you can, begin it. Boldness has genius, power and magic in it. Begin it now.
-Johann von Goethe
When Two Hearts Race... Both Win.
-Dove Chocolate Wrapper
Chroniclemaster1, Founder of www.EarthChronicle.com
A Growing History of our Planet, by our Planet, for our Planet.