function add_feature(feature) {
        document.forms['filter'].form_feature.value = feature;
        document.forms['filter'].form_action.value = 'add_feature';
        document.forms['filter'].submit();
    }

    function del_feature(feature) {
        document.forms['filter'].form_feature.value = feature;
        document.forms['filter'].form_action.value = 'del_feature';
        document.forms['filter'].submit();
    }

    function form_submit(path) {
        if (document.forms['filter'].form_client.value!=0) {
            document.forms['filter'].action = path + document.forms['filter'].form_client.value + '/';
        } else {
            document.forms['filter'].action = path;    
        }
        document.forms['filter'].submit(); 
    } 

    function gotopage(p) {
        document.forms['filter'].page.value = p;
        document.forms['filter'].submit();    
    }