无法在Google脚本编辑器中执行多个if语句

Question

我正在尝试根据Google工作表值自动执行此任务，在此任务中，如果特定单元格的值降至某个特定值以下，则会将邮件发送给相关人员。在尝试执行此操作时，我无法执行多个if语句，但代码仅执行第一个语句。

这是我要使用的代码，

function CheckValue() {
  // Fetch the monthly sales
  var ZebraLabelPaper = SpreadsheetApp.getActive().getSheetByName("Sheet1").getRange("B2");
  var Ulinelabelink = SpreadsheetApp.getActive().getSheetByName("Sheet1").getRange("B3");

  var Zebra_Label_Paper = ZebraLabelPaper.getValue(); 
  var Uline_labelink=Ulinelabelink.getValue();
  var ui = SpreadsheetApp.getUi(); 
  // Check the qty
  if (Zebra_Label_Paper < 30)
  {
      // Fetch the email address
    var emailRange = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Sheet1").getRange("B14");
    var emailAddress = emailRange.getValues();
    // Send Alert Email.
    var message = 'It is time to update the inventory value in the google sheet!'; // Second column
    var subject = 'Your Google Spreadsheet Alert';
    MailApp.sendEmail(emailAddress, subject, message);;
    }

  else if (Uline_labelink < 8)
  {
     // Fetch the email address
    var emailRange = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("Sheet1").getRange("B14");
    var emailAddress = emailRange.getValues();
    // Send Alert Email.
    var message = 'we need 6 qty of Uline_labelink!'; // Second column
    var subject = 'Your Google Spreadsheet Alert';
    MailApp.sendEmail(emailAddress2, subject2, message2);;
  }

}