1 function checkAll() {
2 var selectall = document.getElementById("selectall");
3 var allbox = document.getElementsByName("allbox");
4 if (selectall.checked) {
5 for (var i = 0; i < allbox.length; i++) {
6 allbox[i].checked = true;
7 }
8 } else {
9 for (var i = 0; i < allbox.length; i++) {
10 allbox[i].checked = false;
11 }
12 }
13 }