function updateCalendar(){

    var stjohns = document.getElementById("ctl00_mainContent_chk1")
    var newman = document.getElementById("ctl00_mainContent_chk2")
    var catholic = document.getElementById("ctl00_mainContent_chk3")

    var url = "calendar.aspx?"

    if (stjohns.checked)
    {
      url += "chk1=1"
    }
    else
    {
      url += "chk1=0"
    }
    
    if (newman.checked)
    {
     url += "&chk2=1"
    }
    else
    {
     url += "&chk2=0"
    }

    if (catholic.checked)
    {
     url += "&chk3=1"
    }
    else
    {
     url += "&chk3=0"
    }

    //alert(url);

    document.location = url

}