function show_hide(object){ 
    show = true; 
    obj1 = document.getElementById("master").getElementsByTagName("div"); 
    obj2 = document.getElementById(object); 
    if (obj2.style.display == '') 
        show = false; 
    for (i = 0; i < obj1.length; i++) { 
        obj1[i].style.display = 'none'; 
     } 
    if (show == true) 
        obj2.style.display = ''; 
}