ns4 = (document.layers)? true:false;
ie4 = (document.all)? true:false;

function show(id) {
//	if (ns4) document.layers[id].visibility = "show";
//	else if (ie4) document.all[id].style.visibility = "visible";
	showhide(id, 1);
}

function hide(id) {
//	if (ns4) document.layers[id].visibility = "hide";
//	else if (ie4) document.all[id].style.visibility = "hidden";
	showhide(id, 0);
}

function showhide(szDivID, iState) // 1 visible, 0 hidden
{
   var obj = document.layers ? document.layers[szDivID] :
   document.getElementById ?  document.getElementById(szDivID).style :
   document.all[szDivID].style;
   obj.visibility = document.layers ? (iState ? "show" : "hide") :
   (iState ? "visible" : "hidden");
}

function Is() {
	var agent = navigator.userAgent.toLowerCase();
	this.major = parseInt(navigator.appVersion);
	this.minor = parseFloat(navigator.appVersion);
	this.ns  = ((agent.indexOf('mozilla')!=-1) && ((agent.indexOf('spoofer')==-1) && (agent.indexOf('compatible') == -1)));
	this.ns2 = (this.ns && (this.major == 2));
	this.ns3 = (this.ns && (this.major == 3));
	this.ns4b = (this.ns && (this.minor < 4.04));
	this.ns4 = (this.ns && (this.major >= 4));
	this.ie   = (agent.indexOf("msie") != -1);
	this.ie3  = (this.ie && (this.major == 2));
	this.ie4  = (this.ie && (this.major >= 4));
	this.op3 = (agent.indexOf("opera") != -1);
	this.win   = (agent.indexOf("win")!=-1);
	this.mac   = (agent.indexOf("mac")!=-1);
	this.unix  = (agent.indexOf("x11")!=-1);
}

var is = new Is();