function jumpToNextInput(this_input, next_input)
{
  if(this_input.value.length == this_input.getAttribute('maxlength'))
    document.getElementById(next_input).focus();
}

function differentBillingAddress(this_checkbox, hidden_div)
{
  if(this_checkbox.checked == true)
    document.getElementById(hidden_div).style.display = 'block';
  else
    document.getElementById(hidden_div).style.display = 'none';
}