// Scriptfehler unterdrücken
function blockError(){return true;}
window.onerror = blockError;

function normal(image_name, image_src) {
    eval(document[image_name]).src = 'img/' + image_src + '.gif'; 
}

function over(image_name, image_src) {
    eval(document[image_name]).src = 'img/' + image_src + '_o.gif'; 
}