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 = ''; 
}