I have found a workaround solution for my problem. I can use the plugin on a website that has a simple wordpress theme.
I have installed the plugin on the following domain: onlinetablereservations.com The form works on that domain without a problem.
I will create a link to this website on my other website to do the table booking for the restaurants on the other website: restaurantsincuracao.com
The only thing that I need to do is to have a new serial number created to use on the new website. Because I am not going to use it anymore on the old website. So you can disable the other serial which is: please email me for the serial code.
And please generate a new code for the new website.
Please do this as soon as possible.
Kind Regards,
BY the way your website does not work anymore>
Raymond.