function fadebox() {
 try { document.getElementById('topbox').style.filter='Alpha(Opacity=80)'; document.getElementById('topbox').style.opacity='0.8'; }
 catch (doN) { /* nothing */ }
}

//onload function
function generic() {
 fadebox();
}

//setup onload function
if(typeof window.addEventListener != 'undefined') {
 //.. gecko, safari, konqueror and standard
 window.addEventListener('load', generic, false);
} else if (typeof document.addEventListener != 'undefined') {
 //.. opera 7
 document.addEventListener('load', generic, false);
} else if (typeof window.attachEvent != 'undefined') {
 //.. win/ie
 window.attachEvent('onload', generic);
} else { //** remove this condition to degrade older browsers
 //.. mac/ie5 and anything else that gets this far
 //if there's an existing onload function
 if(typeof window.onload == 'function') {
 //store it
 var existing = onload;
 //add new onload handler
 window.onload = function() {
 //call existing onload function
 existing();
 //call generic onload function
 generic();
 }
} else {
 //setup onload function
 window.onload = generic;
}
}