/*top menu*/
function popm(elem, img, pop){
    var menu = document.getElementById('m'+elem);
    var child = document.getElementById('c'+elem);
    
    //change button img
    menu.src='/images/'+img+'.jpg';
    
    //display child menu
    if(child){
        if( pop ){
            child.style.display = 'inline';
        } else {
            child.style.display = 'none';
        }
    }
}