opera = (navigator.userAgent.indexOf('Opera') >= 0)? true : false;
dom = (document.getElementById)? true : false;
ie4 = (document.all && !dom)? true : false;
nn4 = (document.layers)? true : false;



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 getElement( elemId )
{
    if (dom)
        return document.getElementById(elemId);
    else
        if (ie4)
            return document.all[elemId];
        else
            if (nn4)
                return document.layers[elemId];
    return null;
}