google sheets script save A RANGE to csv

function saveAsCSV() {
  // Prompts the user for the file name
  var fileName = Browser.inputBox("Save CSV file as (e.g. myCSVFile):");
 
  // Check that the file name entered wasn't empty
  if (fileName.length !== 0) {
    // Add the ".csv" extension to the file name
    fileName = fileName + ".csv";
    // Convert the range data to CSV format
    var csvFile = convertRangeToCsvFile_(fileName);
    // Create a file in Drive with the given name, the CSV data and MimeType (file type)
    DriveApp.createFile(fileName, csvFile, MimeType.CSV);
  }
  else {
    Browser.msgBox("Error: Please enter a CSV file name.");
  }
}
 
function convertRangeToCsvFile_(csvFileName) {
  // Get the selected range in the spreadsheet
  var ws = SpreadsheetApp.getActiveSpreadsheet().getActiveSelection();
  try {
    var data = ws.getValues();
    var csvFile = undefined;
 
    // Loop through the data in the range and build a string with the CSV data
    if (data.length > 1) {
      var csv = "";
      for (var row = 0; row < data.length; row++) {
        for (var col = 0; col < data[row].length; col++) {
          if (data[row][col].toString().indexOf(",") != -1) {
            data[row][col] = "\"" + data[row][col] + "\"";
          }
        }
 
        // Join each row's columns
        // Add a carriage return to end of each row, except for the last one
        if (row < data.length-1) {
          csv += data[row].join(",") + "\r\n";
        }
        else {
          csv += data[row];
        }
      }
      csvFile = csv;
    }
    return csvFile;
  }
  catch(err) {
    Logger.log(err);
    Browser.msgBox(err);
  }
}