booking is not working

Hey,
Since i moved my web to another host my booking form is not working.
when i try to push the “book” button, there is no processing, the form is scrolling back up to the top of the form and nothing is happening.
it’s like there is a required field that is empty but this is not the case.
how can i debug the booking process? there is any log file that i can see the problem?
i have the site on 2 different hosts with the same settings and one works and the other doesn’t.
please help me to solve that ??
thanks,
Lioz