function css_f (element) {
  element.style.backgroundColor='#FFF';
}

function css_b(element) {
  element.style.backgroundColor='';
}

function opacity_n (element) {
  element.style.filter='alpha(opacity=100)';
  element.style.MozOpacity='1';
}
function opacity_dd (element) {
  element.style.filter='alpha(opacity=50)';
  element.style.MozOpacity='0.5';
}

function opacity_d (element) {
  element.style.filter='alpha(opacity=70)';
  element.style.MozOpacity='0.7';
}
function gebi(id) {
  return document.getElementById(id);
}