<!--//onSubmit="return formCheck();"
function formCheck(input) 
    {
  
if (document.f.email.value == ""||document.f.email.value.indexOf("@") == -1 ||
            document.f.email.value.indexOf(".") == -1 ) 
        {
        alert("Uw email adres is niet correct.");
		document.f.email.focus();
        return false;
        }
    }
 //-->