function swtch(num, imgname)
{
    if(document.images)
      document[imgname].src = img[num].src;
}

imgsrc = new Array();

imgsrc     [0] =  "img/menu-pl/01_off.gif",
imgsrc     [1] =  "img/menu-pl/01_on.gif",
imgsrc     [2] =  "img/menu-pl/02_off.gif",
imgsrc     [3] =  "img/menu-pl/02_on.gif", 
imgsrc     [4] =  "img/menu-pl/03_off.gif",
imgsrc     [5] =  "img/menu-pl/03_on.gif",
imgsrc     [6] =  "img/menu-pl/04_off.gif",
imgsrc     [7] =  "img/menu-pl/04_on.gif",
imgsrc     [8] =  "img/menu-pl/05_off.gif",
imgsrc     [9] =  "img/menu-pl/05_on.gif",
imgsrc     [10] =  "img/menu-pl/06_off.gif",
imgsrc     [11] =  "img/menu-pl/06_on.gif",
imgsrc     [12] =  "img/menu-pl/07_off.gif",
imgsrc     [13] =  "img/menu-pl/07_on.gif",
imgsrc     [14] =  "img/menu-pl/pics-butons-01_off.gif",
imgsrc     [15] =  "img/menu-pl/pics-butons-01_on.gif",
imgsrc     [16] =  "img/menu-pl/pics-butons-02_off.gif",
imgsrc     [17] =  "img/menu-pl/pics-butons-02_on.gif",
imgsrc     [18] =  "img/menu-pl/pics-butons-03_off.gif",
imgsrc     [19] =  "img/menu-pl/pics-butons-03_on.gif"

if (document.images != null)
{
	img = new Array();
	for (i = 0; i < imgsrc.length; i++)
	{
	img[i] = new Image();
	img[i].src = imgsrc[i];
	}
}

function changeImage(elem, index, lang, extension) {
    var _index, on_offTmp, on_off;
    zero = 0;
    separator = "_";
    pathTmp = elem.src;
    path = "img/menu-"+lang+"/";
    pic = new Image();
    _index = pathTmp.lastIndexOf("_");
    on_offTmp = pathTmp.substring(_index + 1);
    on_off = on_offTmp.substring(0, 2);
    if (on_off == 'on') {
	    if (index > 9) {
		    elem.src = path+index+separator+"off"+extension;
	    }
	    else {
	    	elem.src = path+zero+index+separator+"off"+extension;
    	}
	}
	else {
		if (index > 9) {
			elem.src = path+index+separator+"on"+extension;
		}
		else {
    		elem.src = path+zero+index+separator+"on"+extension;
		}
	}
}