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Upon checking the direct link in your form, which is this one: http://www.jotform.us/form/51073182402141. And your website link, it seems likes you have a code conflict between your website and the form's design by embedding the form's full source code.
I would recommend that you embed using the iFrame code instead, here's a guide on that: http://www.jotform.com/help/148-Getting-the-Form-iFrame-Code. That should make your form to display correctly in your website.
Do let us know if that works.