function getobj(id)
{
    return document.getElementById(id);
}

function getSelVal(id)
{
    var obj = getobj(id);
    var val = obj.options[obj.selectedIndex].value;
    return val;
}

function putDates()
{
    var bd = getSelVal('f_dayb_day');
    var bm = getSelVal('f_dayb_mon');
    var by = getSelVal('f_dayb_year');
    
    var ed = getSelVal('f_daye_day');
    var em = getSelVal('f_daye_mon');
    var ey = getSelVal('f_daye_year');
    
    getobj('fday_b').value = by + '-' + bm + '-' + bd;
    getobj('fday_e').value = ey + '-' + em + '-' + ed;
    
    alert(getobj('fday_b').value + ' - ' + getobj('fday_e').value);
}