why won't my form work on a Mac computer using safari?

I am the web developer for I Said Sit!. We have had an ongoing problem with our registration page at: http://isaidsit.com/index.php/registerform

We are having a major problem that I hope you can help with. I have had 4 programmers look at the problem and cannot find where there is an issue. We have installed the site on our test sever and we cannot duplicate the process. I installed it on my personal server and we didn't get the errors, it worked fine in all the browsers on several different traditional and mobile devices.

On the following page we have a big registration form that will not work in Safari on a computer. We can use the form on an iPad or and iPhone or PC using Safari without any problems, if it's used on a Mac computer we get several different err开发者_如何学编程ors:

1. After you hit the submit button it gives you a blank form and you can't more forward
2. After you hit the submit button it will give an error that the url is not accessible

Those are the most often reported problems.

Tested OK on an iMac running MacOS 10.6.7 and Safari 5.0.5. (Abandoned at the Credit Card Payment step.)

The markup, as mentioned by @David Thomas, is atrocious - 91 errors from the W3C Validator, and a quick visual inspection shows what looks like another complete HTML page being loaded into the body of the HTML page.

Some general feedback on the form (feel free to ignore this if you want):

• That form is incredibly long. Maybe look at cutting it into smaller sections so the user gets an idea of their progress would be nice. This is a jQuery plugin which does just that, but there may be clones for the javascript framework you are using.
• Mark which fields are compulsory and which are optional.
• Possibly include the Indemnity Waiver and Payment subforms into the same form (only if you do adopt Point 1) - seems silly you have one massive form which then throws to two smaller forms individually.