document.getElementById("tab4").innerHTML = '<p>Click on the dates to see the work done.</p><table id="calendar"><tr><td><a href="#" id = "week_decr" onclick="return false;"> < </a></td><td id="calendar_week"></td><td><a href="#" id="week_incr" onclick="return false;"> > </a></td></tr></table><table id ="calendar_days"><tr><td><a href="#" id="calendar_day1" onclick="return false;">1</a></td><td><a href="#" id="calendar_day2" onclick="return false;">2</a></td><td><a href="#" id="calendar_day3" onclick="return false;">3</a></td><td><a href="#" id="calendar_day4" onclick="return false;">4</a></td><td><a href="#" id="calendar_day5" onclick="return false;">5</a></td><td><a href="#" id="calendar_day6" onclick="return false;">6</a></td><td><a href="#" id="calendar_day7" onclick="return false;">7</a></td></tr></table><p id="calendar_head"></p><table id="calendar_work"></table>';