//假设已经设置好变量box(装button的盒子),buttonN个;
var box1 = document.getElementById('box1');
var box2 = document.getElementById('box2');
box1.onclick = function(e){
if(e.target.tagName == "BUTTON"){
box2.appendChild(e.target.cloneNode(true));
box1.removeChild(e.target);
}
}