function ChangeDate(el) {
    if (el.name == 'DateMonth') param = 'month';
    if (el.name == 'DateYear') param = 'year';
    document.location.href = '?' + param + '=' + el.value;
}

// 2use popup() function: <a href="javascript:;" onClick="javascript:popup('name', '#link', 0, 0, 300, 150, 0, 0, 1, 1, 1); return false;"></a>
function popup(name, url, left, top, width, height, toolbar, menubar, statusbar, scrollbar, resizable){
        var wint = (screen.height - height) / 2;
        var winl = (screen.width - width) / 2;
        toolbar_str = toolbar ? 'yes' : 'no';
        menubar_str = menubar ? 'yes' : 'no';
        statusbar_str = statusbar ? 'yes' : 'no';
        scrollbar_str = scrollbar ? 'yes' : 'no';
        resizable_str = resizable ? 'yes' : 'no';
        window.open(url, name, 'left='+winl+',top='+wint+',width='+width+',height='+height+',toolbar='+toolbar_str+',menubar='+menubar_str+',status='+statusbar_str+',scrollbars='+scrollbar_str+',resizable='+resizable_str);
}