在此处发布解决方案，以便其他人可以使用它。

Posting as a solution here so others can use it.

function ShowRBL6() {
            if (document.getElementById('<% = MyCheckBox.ClientID %>').checked == true)
                document.getElementById('<% = RBL6.ClientID %>').style.display = "block";
            else
                document.getElementById('<% = RBL6.ClientID %>').style.display = "none";

        }

因此下一次点击也将用于取消检查将被处理。

so the next click will be also for unchecking will be handled.