function sendAllRowsToChatworkExceptLastRow() {
var spreadsheet = SpreadsheetApp.getActiveSpreadsheet();
var sheet = spreadsheet.getSheetByName('GAS');
var lastRow = sheet.getLastRow();
for (var i = lastRow; i > 1; i--) {
var content = sheet.getRange(i, 2).getValue();
// Create a message to send to ChatWork.
var message = "[info][title]this is task today ; [/title]" +
"Content: " + content + "\n" +
"[/info]";
// Send the message to ChatWork.
var client = ChatWorkClient.factory({token: "your token"});
client.sendMessage({room_id: "room_id", body: message});
}
}