var state = 'none';
function showhide(layer_ref){
if(state == 'block'){
state = 'none';
}else{
state = 'block';
}
if(document.all){ //IS IE 4 or 5 (or 6 beta)
eval("document.all." +layer_ref+ ".style.display = state");
}
if (document.layers) { //IS NETSCAPE 4 or below
document.layers[layer_ref].display = state;
}
if (document.getElementById &&!document.all) {
hza = document.getElementById(layer_ref);
hza.style.display = state;
}
}