function setPeriod()
{
    var heute = new Date();
    var tagHeuteValue = heute.getDate();
    var monatHeuteValue = heute.getMonth()+1;
    var jahrHeuteValue = heute.getYear();

    // MSIE rechnet Jahreszahlen ab 0, Mozilla ab 1900
    if (jahrHeuteValue < 1900)
    jahrHeuteValue += 1900;

    var todayElemArr = document.getElementsByName("fs[dates][today]");
    var tomonthElemArr = document.getElementsByName("fs[dates][tomonth]");
    var toyearElemArr = document.getElementsByName("fs[dates][toyear]");

    todayElemArr[0].value = tagHeuteValue;
    tomonthElemArr[0].value = monatHeuteValue;
    toyearElemArr[0].value = jahrHeuteValue;

    var zeitraum = document.getElementById("zeitraum").value;
    if(zeitraum == 7 || zeitraum == 30 || zeitraum == 90)
    {
        var frueher = new Date(jahrHeuteValue, monatHeuteValue-1, tagHeuteValue - zeitraum);
    }
    if(zeitraum == "1jahr")
    {
        var frueher = new Date(jahrHeuteValue-1, monatHeuteValue-1, tagHeuteValue);
    }
    if(zeitraum == "2jahr")
    {
        var frueher = new Date(jahrHeuteValue-2, monatHeuteValue-1, tagHeuteValue);
    }
    if(zeitraum == "3jahr")
    {
        var frueher = new Date(jahrHeuteValue-3, monatHeuteValue-1, tagHeuteValue);
    }
    if(zeitraum == "alles")
    {
        var frueher = new Date(1996, 0, 1);
    }

    if (frueher)
    {
    var tagFrueherValue = frueher.getDate();
    var monatFrueherValue = frueher.getMonth()+1;
    var jahrFrueherValue = frueher.getYear();

    // MSIE rechnet Jahreszahlen ab 0, Mozilla ab 1900
    if (jahrFrueherValue < 1900)
      jahrFrueherValue += 1900;

    var fromdayElemArr = document.getElementsByName("fs[dates][fromday]");
    var frommonthElemArr = document.getElementsByName("fs[dates][frommonth]");
    var fromyearElemArr = document.getElementsByName("fs[dates][fromyear]");

    fromdayElemArr[0].value = tagFrueherValue;
    frommonthElemArr[0].value = monatFrueherValue;
    fromyearElemArr[0].value = jahrFrueherValue;
    }
}

function resetPeriod()
{
    document.getElementById("zeitraum").value = "---";
}


var todayElem = document.getElementsByName("fs[dates][today]")[0];
var tomonthElem = document.getElementsByName("fs[dates][tomonth]")[0];
var toyearElem = document.getElementsByName("fs[dates][toyear]")[0];

var fromdayElem = document.getElementsByName("fs[dates][fromday]")[0];
var frommonthElem = document.getElementsByName("fs[dates][frommonth]")[0];
var fromyearElem = document.getElementsByName("fs[dates][fromyear]")[0];

if (todayElem.addEventListener)
{
    // Mozilla, Opera
    todayElem.addEventListener("change", resetPeriod, false);
    tomonthElem.addEventListener("change", resetPeriod, false);
    toyearElem.addEventListener("change", resetPeriod, false);
    
    fromdayElem.addEventListener("change", resetPeriod, false);
    frommonthElem.addEventListener("change", resetPeriod, false);
    fromyearElem.addEventListener("change", resetPeriod, false);
}
else if (todayElem.attachEvent)
{
    // MSIE
    todayElem.attachEvent("onchange", resetPeriod);
    tomonthElem.attachEvent("onchange", resetPeriod);
    toyearElem.attachEvent("onchange", resetPeriod);
    
    fromdayElem.attachEvent("onchange", resetPeriod);
    frommonthElem.attachEvent("onchange", resetPeriod);
    fromyearElem.attachEvent("onchange", resetPeriod);
}


function getVar(name)
{
    get_string = document.location.search;         
    return_value = '';

    do
    {
        name_index = get_string.indexOf(name + '=');

        if(name_index != -1)
        {
            get_string = get_string.substr(name_index + name.length + 1, get_string.length - name_index);
          
            end_of_value = get_string.indexOf('&');
            if(end_of_value != -1)                
            value = get_string.substr(0, end_of_value);                
            else                
            value = get_string;                

            if(return_value == '' || value == '')
                return_value += value;
            else
                return_value += ', ' + value;
        }
    } while(name_index != -1)

    space = return_value.indexOf('+');
    while(space != -1)
    { 
        return_value = return_value.substr(0, space) + ' ' + 
        return_value.substr(space + 1, return_value.length);
                     
        space = return_value.indexOf('+');
    }

    return(return_value);        
}

var zeitraum = getVar("zeitraum");

if (zeitraum)
    document.getElementById("zeitraum").value = zeitraum;