var cur_page;
var cur_deep = 0;
function set_nav(page, deep)
{
	cur_deep = deep;
	if(bttn = document.getElementById("bttn_"+page)){ bttn_down(bttn); bttn.style.color = "red"; cur_page = page;}
}
function bttn_down(bttn, name)
{
	if(name){bttn = document.getElementById("bttn_"+name);}
	if(bttn.getAttribute("id") != "bttn_"+cur_page)
	{
		var drill = ""; if(cur_deep > 0){for(i = 0; i < cur_deep; i++){drill += "../";}}
		bttn.style.color = "blue";
		if(b = getFirstClassName(bttn, "l")){b.style.backgroundImage="url('"+drill+"assets/bttn_down_left.jpg')";}
		if(b = getFirstClassName(bttn, "c")){b.style.backgroundImage="url('"+drill+"assets/bttn_down_center.jpg')";}
		if(b = getFirstClassName(bttn, "r")){b.style.backgroundImage="url('"+drill+"assets/bttn_down_right.jpg')";}
	}
}
function bttn_up(bttn, name)
{
	if(name){bttn = document.getElementById("bttn_"+name);}
	if(bttn.getAttribute("id") != "bttn_"+cur_page)
	{
		var drill = ""; if(cur_deep > 0){for(i = 0; i < cur_deep; i++){drill += "../";}}
		bttn.style.color = "black";
		if(b = getFirstClassName(bttn, "l")){b.style.backgroundImage="url('"+drill+"assets/bttn_left.jpg')";}
		if(b = getFirstClassName(bttn, "c")){b.style.backgroundImage="url('"+drill+"assets/bttn_center.jpg')";}
		if(b = getFirstClassName(bttn, "r")){b.style.backgroundImage="url('"+drill+"assets/bttn_right.jpg')";}
	}
}
function getFirstClassName(el, n)
{
	var els = new Array();
	els = getElementsByClass(el, "*", n);
	if(els.length > 0){return els[0];}
	return false;
}
function getElementsByClass(oElm, strTagName, strClassName)
{
	var arrElements = (strTagName == "*" && oElm.all) ? oElm.all : oElm.getElementsByTagName(strTagName);
	var arrReturnElements = new Array(); strClassName = strClassName.replace(/\-/g, "\\-");
	var oRegExp = new RegExp("(^|\\s)" + strClassName + "(\\s|$)");
	var oElement;
	for(var i=0; i<arrElements.length; i++)
	{
		oElement = arrElements[i];      
		if(oRegExp.test(oElement.className))
		{
			arrReturnElements.push(oElement);
		}   
	}
	return (arrReturnElements)
}