[最佳答案] function ok_to_delete() { if (rows_selected()) { return confirm("Are you sure you want to delete the selected members?"); } else { alert("Please select a row first."); return false; } } function rows_selected() { var ids = document.listing_form.elements['ids[]']; var length = ids.length; for (var c1 = 0; c1 < length; c1++) { if (ids[c1].checked) { return true; } } return false; } Your form should then contain: <form method="post" onsubmit="return ok_to_delete()">