Get calendar entries to spreadsheet on Google Apps (see Tools -> Script Editor on Google Spreadsheets)

calFetch.js

function onOpen() {
  // create menu entry for starting calFetch script
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var menuEntries = [{name: "Get calendar entries", functionName: "calFetch"}];
  ss.addMenu("Calendar", menuEntries); 
  
}

function calFetch() {
  // get calendar entries and show them and total times
  
  var ss = SpreadsheetApp.getActiveSpreadsheet();
  var sheet = ss.getSheets()[0];
  
  // hard coded cells to get input data
  var eventsFrom = sheet.getRange(1, 2).getValue(); 
  var eventsTo = sheet.getRange(1, 4).getValue(); 
  var calName = sheet.getRange(1, 6).getValue();

  var cal = CalendarApp.getCalendarsByName(calName);

  var events = cal[0].getEvents(eventsFrom, eventsTo);

  sheet.getRange(2, 1).setValue("Start"); 
  sheet.getRange(2, 2).setValue("Title");
  sheet.getRange(2, 3).setValue("Description"); 
  sheet.getRange(2, 4).setValue("Duration  (h)"); 
  
  sheet.getRange(2, 6).setValue("Title"); 
  sheet.getRange(2, 7).setValue("Total duration (h)"); 

  durations = {}
  if (events[0]) {
    // display each entry
    for (var i = 0; i < events.length; i++) {
//  Browser.msgBox(events[i].getDescription());
    var startTime = events[i].getStartTime();
    var endTime = events[i].getEndTime();
    var duration = (endTime - startTime) / (60*60*1000); // scale ms -> hour
    var title = events[i].getTitle();
    sheet.getRange(i+3, 1).setValue(startTime);
    
    sheet.getRange(i+3, 2).setValue(title);
    sheet.getRange(i+3, 3).setValue(events[i].getDescription());
    sheet.getRange(i+3, 4).setValue(duration);
 
    if (durations[title]) {
      durations[title] = durations[title] + duration;
    } else {
      durations[title] = duration; 
    }
  }
  }
  if (durations) {
    var i = 3;
    for ( title in durations) {
      // display durations for each entry
      sheet.getRange(i, 6).setValue(title);
      sheet.getRange(i, 7).setValue(durations[title]); 
      i += 1; 
      sheet.getRange(i+2, 3).setValue(events[i].getDescription());
    }
  }
}

Are you using any external libraries, because I literally copied and pasted this in and filled the dependent cells, but it still didn't even compile?