はてなダイアリーの記事を一括でチェック入れて削除するスクリプト。

hateda-delete.js

var deleteForm = null;
for (var i = 0; i < document.forms.length; i++) {
    var action = document.forms[i].getAttribute("action");
    if (action && action.match(/delete$/))
        deleteForm = document.forms[i];
}

tdList = document.getElementsByClassName("td-checkbox");
for (i = 0; i < tdList.length; i++) {
    tdList[i].children[0].checked = true;
}

deleteForm.submit();