JS选择checkbox

<script>

    window.onload = function () {

        //获取checkbox

        var ids1 = document.getElementsByName('VoteOption1');

        //获取值

        var choose1 = document.getElementById('ctl00_ContentPlaceHolder1_Facilities_864').value.split(',');

        for (var i = 0; i < ids1.length; i++) {

            if (contains(choose1, ids1[i].value))

            { ids1[i].checked = true; }

        }

    }

    //a:值

    //obj:checkbox

    function contains(a, obj) {

        var i = a.length;

        while (i--) {

            if (a[i] === obj) {

                return true;

            }

        }

        return false;

    }

</script>