change_opacity_onmouseover = function(obj) {
    obj.style.opacity=.7;
    if  (BrowserDetect.browser == 'Explorer') {
        obj.filters.alpha.opacity=70;
    }
  }
  change_opacity_onmouseout = function(obj) {
    obj.style.opacity=1;
    if  (BrowserDetect.browser == 'Explorer') {
        obj.filters.alpha.opacity = 100;
    }
  }