title: sendNotification continues to send emails if any cell in row with value trigger is updated
body: <p>I'm using sendNotification to trigger an email when column 'G' has a value of 'All Components to DC'. But, the issue I am having is that when the column already has the data 'All Components at DC' and another column in the same row is updated (with any value), the script is checking column 'G' again and seeing the 'All Components at DC' and re-sending the same email.</p>
  
  <p>How would the script need to be re-written so that the notification is only sent when column 'G' is updated and ignores the other cells in the same row?</p>
  
  <pre><code>function sendNotification(e){
    var ss = SpreadsheetApp.getActiveSpreadsheet();
    var sheet = ss.getActiveSheet();
    var cell = ss.getActiveCell().getA1Notation();
    var row = sheet.getActiveRange().getRow();
    var cellvalue = ss.getActiveCell().getDisplayValue().toString();
  
    if(sheet.getRange('G'+row).getValue()=='All Components at DC')
    {
      var recipients = "xxx@xxx.com";
      var subject = "Delivered Items"
      var message = sheet.getRange('A'+ sheet.getActiveCell().getRowIndex()).getValue() + '\n TITLE: ' + sheet.getRange('F'+ sheet.getActiveCell().getRowIndex()).getValue() + '\n LANGUAGE: ' + sheet.getRange('E'+ sheet.getActiveCell().getRowIndex()).getValue()
      var body = sheet.getName() + ' has been updated. Visit ' + ss.getUrl() + '\n ROW: ' + row + '\n DATE: ' + message + '\n COMMENT: ' + cellvalue;
      var valColB=e.range.getSheet().getRange(e.range.getRow(),2).getValue();
      MailApp.sendEmail(recipients, subject, body);
    }
  }
  </code></pre>