dom = (document.getElementById) ? true : false;
nn4 = (document.layers) ? true : false;
ie = (document.all) ? true : false;
ie4 = ie && !dom;
Mac = (navigator.appVersion.indexOf("Mac") != -1);
opera = (navigator.userAgent.indexOf("Opera")!=-1);


function showElem(elemId) {
if (dom) document.getElementById(elemId).style.visibility = "visible";
	else if (ie4) document.all[elemId].style.visibility = "visible";
		else if (nn4) document.layers[elemId].visibility = "show";
}

function hideElem(elemId) {
if (dom) document.getElementById(elemId).style.visibility = "hidden";
	else if (ie4) document.all[elemId].style.visibility = "hidden";
		else if (nn4) document.layers[elemId].visibility = "hide";
}

function putElem(elemId) {
if (dom) document.getElementById(elemId).style.display = "block";
	else if (ie4) document.all[elemId].style.display = "block";
}

function removeElem(elemId) {
if (dom) document.getElementById(elemId).style.display = "none";
	else if (ie4) document.all[elemId].style.display = "none";
}

function moveElem(idname,x,y)
{
if (dom)
	with(eval(idname)){
		style.left = x;
		style.top = y;
	}
else if(nn4){
		document.layers[idname].left=x;
		document.layers[idname].top=y;
	}
}

function changeElem(elemId)
{
if(dom) 
	if(document.getElementById(elemId).style.display == "block")
		document.getElementById(elemId).style.display = "none"
	else
		document.getElementById(elemId).style.display = "block"

else if (ie4) 
	if(document.all[elemId].style.display == "block")
		document.all[elemId].style.display = "none";
	else
		document.all[elemId].style.display = "block";
}

function exchangeElem(elemId)
{
if(dom) 
	if(document.getElementById(elemId).style.visibility == "hidden")
		document.getElementById(elemId).style.visibility= "visible"
	else
		document.getElementById(elemId).style.visibility= "hidden"

else if (ie4) 
	if(document.all[elemId].style.visibility== "hidden")
		document.all[elemId].style.visibility= "visible";
	else
		document.all[elemId].style.visibility= "hidden";
else if (nn4) 
	if(document.layers[elemId].visibility=="hide")
		document.layers[elemId].visibility="show";
	else
		document.layers[elemId].visibility="hide";



}