var curr_btn = null;
var curr_sub = null;

function fnButtonOn(buttonId, type){
	var button = document.getElementById(buttonId);
	
	if (type == 'on'){
		button.src = button.src.replace('_off', '_on');
	} else {
		if(curr_btn != buttonId) {
			button.src = button.src.replace('_on', '_off');
		}
	}
}

function fnOpenSubNav(sender, subMenu){
	fnClearTimer();
	if (curr_sub != null) {
		fnCloseSubNav(curr_sub);
	}
	
	var submenu = document.getElementById('sub' + subMenu);
	curr_sub = subMenu;
	
	if (submenu) {
		submenu.style.display = 'block';
		submenu.style.left = (fnFindCenterPos(sender, subMenu) - (submenu.offsetWidth / 2)) + 'px';
	}
}

//function 

function fnCloseSubNavTimed(subMenu){
	oTimer = eval("setTimeout('fnCloseSubNav("+subMenu+")', 500)");
}

function fnCloseSubNav(subMenu){

	var submenu = document.getElementById('sub' + subMenu);
	submenu.style.display = 'none';
	curr_sub = null;
}

function fnClearTimer(){
	try { clearTimeout(oTimer);}
	
	catch (ex) { }	
}

function fnFindCenterPos(obj, subMenu) {
	var curleft = 0;
	if (obj.offsetParent) {
		curleft = obj.offsetLeft
		while (obj = obj.offsetParent) {
			curleft += obj.offsetLeft
		}
	}
	
	switch(subMenu)
	{
		case 7705: //over ons
			curleft += 35;
			break;
		case 7706: //nieuws
			curleft += 45;
			break;
		case 7707:
			curleft += 44;
			break;
		case 7708: //werken bij
			curleft += 50;
			break;
		case 7709: //verenigingen
			curleft += 49;
			break;
		default:
			curleft = curleft;
	}
	
	return curleft;
}