function Search() {
  var sheet = SpreadsheetApp.getActiveSheet();
  var row = 2;

  // Clear existing search results
  sheet.getRange(2, 1, sheet.getMaxRows() - 1, 4).clearContent();

  // Which Gmail Label should be searched?
  var label = sheet.getRange('F3').getValue();

  // Get the Regular Expression Search Pattern
  var pattern = sheet.getRange('F4').getValue();

  // Retrieve all threads of the specified label
  var threads = GmailApp.search('in:' + label);

  for (var i = 0; i < threads.length; i++) {
    var messages = threads[i].getMessages();

    for (var m = 0; m < messages.length; m++) {
      var msg = messages[m].getBody();

      // Does the message content match the search pattern?
      if (msg.search(pattern) !== -1) {
        // Format and print the date of the matching message
        sheet.getRange(row, 1).setValue(Utilities.formatDate(messages[m].getDate(), 'GMT', 'yyyy-MM-dd'));

        // Print the sender's name and email address
        sheet.getRange(row, 2).setValue(messages[m].getFrom());

        // Print the message subject
        sheet.getRange(row, 3).setValue(messages[m].getSubject());

        // Print the unique URL of the Gmail message
        var id = 'https://mail.google.com/mail/u/0/#all/' + messages[m].getId();
        sheet.getRange(row, 4).setFormula('=hyperlink("' + id + '", "View")');

        // Move to the next row
        row++;
      }
    }
  }
}