this.ie4  = document.all ? 1 : 0
	this.ns4 = document.layers ? 1 : 0
	this.dom = document.getElementById ? 1 : 0
	
	var x = 5;
	var y = 12;
	
	var timVar=0;

	divArray = new Array("about","articles","books","cont","seminars","odds");
	divArrayLen = divArray.length;


function show(id) {

	hide_all(id);

	clearTimeout(timVar);

//	setpos(id);			// reset position of the div for resizing window case
		
	if (ns4) document.layers[id].visibility = "show";
	if (ie4) document.all[id].style.visibility = "visible";
	if(dom)  document.getElementById(id).style.visibility ="visible";
}

function hide_all(id) {
	for(i=0; i<divArrayLen; i++) {
		if(id!=divArray[i]) hide(divArray[i]);
	}
}

function hide_d(id) {
	timVar = setTimeout("hide('"+id+"')",700);
}

function hide(id) {
	if (ns4) document.layers[id].visibility = "hide";
	if (ie4) document.all[id].style.visibility = "hidden";
	if(dom) document.getElementById(id).style.visibility ="hidden";
}

// upper div has the same name + U - e.g. id='hidden_div_name' and id='hidden_div_nameU'

function setpos(id) {

	idU = id+"U";
	xPos = 173;			// shift for X position

if (ns4) 	document.layers[id].left = document.layers[idU].x+xPos;
if (ie4) 	document.all[id].style.left = document.all[idU].style.offsetLeft+xPos;
if (dom) 	document.getElementById(id).style.left=document.getElementById(idU).offsetLeft+xPos;

}