Why I'am a getting an error when I submit my form?

Because that particular form doesn't exist. Please let us know the URL here so we can check it for you.

In your screenshot, the form ID is 11330046337 but looks like it's a wrong form ID. If the form is embedded, please let us know the page URL here so we can inspect it for you.

Thanks

The url I get when I submit the form is http://www.jotform.com/submit.php.
...

Yes, I saw that. I'm sorry, but I need to know the "Form URL". If you are in the form builder, simply click the "Preview" button to get the form URL:

Again, if the form is embedded to your website, please let us know the page URL here so we can inspect it for you.

Thanks

I'm sorry I didn't understand what url you needed. The Form Url is
http://form.jotform.us/form/52315435545150
...

No worries. 

But I was able to submit the form without getting that particular error:

If you have embedded this form, please use our iframe method: https://www.jotform.com/help/148-Getting-the-Form-iFrame-Code.

Thanks