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

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;
} 

function showHideDiv(divname){
	if (document.getElementById(divname).style.display=='none'){
		putElem(divname);
		return 1;
	}
	else {
		removeElem(divname);
		return 1;
	}

}