hello all

I am a newbie and having problems...if someone can got to my website that i am testing and tell me or guide me as to how to change the color and the text of the warning that comes up when you add the product to the cart...there is only one product there it is the zoom control...I have some attributes there that I have put there but my question pertains to the warning that comes up when you dont choose one of the attributes...also is there a way to change the text"Please choose one" that preceeds the attributes?

thanks for anybodys help

Erik