var ie = (document.all) ? true : false;

function findObject(objid){
    var elements = (ie) ? document.all : document.getElementsByTagName('*');
    for (i=0; i<elements.length; i++){
        if (elements[i].id.search(objid) != -1){
            return elements[i];
        }
    }
}

function btn_onMouse(id,action){
    var obj = findObject(id)
    if(action == 'move')
        obj.style.backgroundPosition='0px -27px';
    else
    obj.style.backgroundPosition='0px 0px';
}