You have some form elements that are badly named.
When naming form elements you must confirm to the following rules:
1) Form element names may contain only numbers and letters. The only exception is the underscore (_) character.
2) the first character in a name must be a letter.
3) You may not use spaces.
the following form elements are causing java script errors to occur which is breaking the validation:
<input type="text" name="e-mail" size="44" tabindex="1">
<input type="checkbox" value="informatie" name="carpette bordure">