function ClickCheckbox(id) {
  // If switched off
  if(document.forms[0].remember.value == 0) {

    document.forms[0].remember.value = 1;
    document.getElementById(id).src  = 'img/checkbox_checked.gif';

  }else {
    document.forms[0].remember.value = 0;
    document.getElementById(id).src  = 'img/checkbox_empty.gif';
  }
}