var domain_url = 'http://www.swingjevrij.nl/';
var active_img;
var page_name;
var i=0;
var td_left='';


if(document.location.href.search(/^.*?([^\/.]*)\.s?html?$/i) != -1) 
	page_name = RegExp.$1;
else page_name = 'index';
		

function init_menus()
{
	if(td_left) return;
	
	td_left = getObj('left_menu'); //left menu cell
	
	if(td_left) var col_img = td_left.getElementsByTagName("IMG"); //left menu images

	if(col_img)
		for(i=0;i<col_img.length;i++){
			if(col_img[i].src.search(page_name) != -1){
				col_img[i].src = col_img[i].src.replace(/(_active)?\.gif$/,'_active.gif'); //current item
				active_img = col_img[i].src;
							}
			col_img[i].onmouseover = event_img; 
			col_img[i].onmouseout = event_img;	
		}
}
		

/************************************************/
function event_img(e)
{
	if(!e) e=event;
	var img=this;
	
	if(!e || !img.tagName || img.tagName != 'IMG') return;

	if(img.src != active_img) {
		if(e.type == 	'mouseover'){ 
			img.src = img.src.replace(/(_active)?\.gif$/,'_active.gif');
			img.id=img.src;
			changeOpac(0,img.id);
			opacity(img.id, 5, 65, 700);

 		} else 	{
			img.src = img.src.replace(/_active/g,'');
 			img.id = img.src;
 			changeOpac(100,img.id);
 		}
	}
}


/************************************************/
	
function getObj(obj_name)
{
	return document.getElementById ? document.getElementById(obj_name) : eval(obj_name);
}
		
/************************************************/
//see http://www.brainerror.net/scripts_js_blendtrans.php
	
function opacity(id, opacStart, opacEnd, millisec) { 
    //speed for each frame 
    var speed = Math.round(millisec / 100); 
    var timer = 0; 

    //determine the direction for the blending, if start and end are the same nothing happens 
    if(opacStart > opacEnd) { 
        for(var i = opacStart; i >= opacEnd; i--) { 
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
            timer++; 
        } 
    } else if(opacStart < opacEnd) { 
        for(var i = opacStart; i <= opacEnd; i++) 
            { 
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed)); 
            timer++; 
        } 
    } 
} 

//change the opacity for different browsers 
function changeOpac(opacity, id) { 
    var img = document.getElementById(id); 
    if(img) {
    	img.style.opacity = (opacity / 100); 
    	img.style.MozOpacity = (opacity / 100); 
    	img.style.KhtmlOpacity = (opacity / 100); 
    	img.style.filter = "alpha(opacity=" + opacity + ")"; 
    }
}