var state = 'none';

function showhide(layer_ref)
{
if (state == 'block') {state = 'none';}
else {state = 'block';}

if (document.all) {eval("document.all." + layer_ref + ".style.display = state");}
//if (document.all) {eval(layer_ref + ".style.display = state");}
if (document.layers) {document.layers[layer_ref].display = state;}
if (document.getElementById &&!document.all) {hza = document.getElementById(layer_ref); hza.style.display = state;}
};