dom = (document.getElementById)? true : false;
nn4 = (document.layers)? true : false;
ie4 = (document.all && !dom)? true : false;

 function showPic(picAddress) { 
 document.getElementById('piclayer').innerHTML =  '<img src="'+picAddress+'" style="border:1px solid; border-color:#FFFFFF" onClick="hidePic(); return false;">'; 
document.getElementById('piclayer').style.display = "block"; 
} 
function hidePic() {  
if (dom) document.getElementById('piclayer').style.display = "none"; 
}