复选框全选2
function checkOne(obj){
if(!obj.checked){
document.forms[0].selectAllCK.checked = obj.checked;
}
var b = true;
var arr = document.getElementsByName(obj.name);
for(var i=0;i<arr.length;i++){
if(!arr[i].checked){b=false; break;}
}
document.forms[0].selectAllCK.checked = b;
}