function showtb(tbnum){
if (getObject("tbtype" + tbnum).style.display == "none"){
getObject("tbtype" + tbnum).style.display='';
getObject("img" + tbnum ).src='images/index_flo.gif';
}
else{
getObject("tbtype" + tbnum).style.display='none';
getObject("img" + tbnum).src='images/index_unflo.gif';
}
}

function getObject(objectId) {
    if(document.getElementById && document.getElementById(objectId)) {
 // W3C DOM
 return document.getElementById(objectId);
    } else if (document.all && document.all(objectId)) {
 // MSIE 4 DOM
 return document.all(objectId);
    } else if (document.layers && document.layers[objectId]) {
 // NN 4 DOM.. note: this won't find nested layers
 return document.layers[objectId];
    } else {
 return false;
    } 
}