captcha

I need to add a captcha on my sign up page. My website is [login to view URL] and the page is [login to view URL] I need to replace the wording at the bottom to say: If you agree to the above terms and conditions, please type in the code displayed below. (rather than the I Agree) . Someone has a script attacking my sign up form and I need the captcha. Also my sign up form when being used with Internet explorer shows a further box with additional questions in two locations but doesn't work with Firefox. I would like it to work with both. The locations are after answering the following two questions: 1) Did you file a United States tax return for any previous year? and 2) I estimate the money spent on wagers in the USA to be: I use Macromedia Dreamweaver 2004 to upload my pages. Also the captcha should be an easy to read one as my clients are not computer savy and wierd warped words will reduce sign ups.