var ON = '2';
var OFF = '1';

var ext = ".gif"
var dir = "btnpics/"

var menuImages = new Array();
menuImages[0] = 'home';
menuImages[1] = 'shaolin';
menuImages[2] = 'teaching';
menuImages[3] = 'courses';
menuImages[4] = 'links';
menuImages[5] = 'etusivu';
menuImages[6] = 'opetus';
menuImages[7] = 'kurssit';
menuImages[8] = 'linkit';
menuImages[9] = 'finnish';
menuImages[10] = 'english';

// Preload images
var preloadImages = new Array();
var counter = 0;
for (i in menuImages) {
    preloadImages[counter] = new Image();
    preloadImages[counter].src = dir + menuImages[counter] + ON + ext;
    counter++;
}

function changeImage(img_id, img_src) {
    document.getElementById(img_id).src = img_src;
}

function roll(target, state) {
    
    var accept = 1;
    for (x in menuImages) {
	if (target == x) {
	    accept = 1;
	    break;
	}
    }
    if (accept == 1) {
	var img = dir + target + state + ext; //dir.concat(target, state, ext);
	changeImage(target, img);
    }
}