var dom = document.getElementById ? true : false;
var ie4 = ((document.all) && (!dom)) ? true : false; 
var ns4 = document.layers ? true : false;
var opera = navigator.userAgent.indexOf('Opera') != -1 ? true : false; 
var dhtml = dom ? true : ie4 ? true : ns4 ? true : false;
var timer, i, menuId; // n�kolik prom�nn�ch, se kter�mi budete pracovat


function swap_card(card) {

    for (i=0; i<3; i++) {
	if ("card_1_" + i == card) {
	    document.getElementById("card_1_" + i).className = 'active';
	    document.getElementById("body_" + i).style.visibility = 'visible';
	    
	}
	else {
	    document.getElementById("card_1_" + i).className = 'normal';
	    document.getElementById("body_" + i).style.visibility = 'hidden';
	}
    }

}




function swap_card2(prefix, id) {

    for (i = 1; i <= 12; i++) {
	elem = prefix + i;

	if (i == id) {
	    document.getElementById(elem).className = 'active';
	}
	else {
	    document.getElementById(elem).className = 'normal';
	}
    }

}