/* Clear searchbox-input field */
function clear_text() {
    var search_input = document.getElementById("keyword");
    if (search_input.value == 'zoek op trefwoord') {
        search_input.value = "";
    }
}

/* Set default text in searchbox-input field */
function set_text() {
    var search_input = document.getElementById("keyword");
    if (search_input.value == '') {
        search_input.value = "zoek op trefwoord";
    }
}

function showhide_submenu(submenu_id) {
    for (i=1;i<6;i++) {
        if (submenu_id == i) {
            if (document.getElementById("submenu_"+i) != null) {
                if (document.getElementById("submenu_"+i).style.display == 'block'){ 
                    document.getElementById("submenu_"+i).style.display = 'none';   
                } else {                                                     
                    document.getElementById("submenu_"+i).style.display = 'block';     
                }            
            }
        } else {
            if (document.getElementById("submenu_"+i) != null) {
                document.getElementById("submenu_"+i).style.display = 'none'; 
            }
        }
    }
}

function make_item_active(menu_id) {
    if (document.getElementById("menuitem_"+menu_id)) {
        for(i=1;i<6;i++){
            if (menu_id == i){
                if(document.getElementById("menuitem_"+menu_id).className == 'item_nonactive'){    
                    document.getElementById("menuitem_"+menu_id).className = 'item_active';       
                } else {
                    document.getElementById("menuitem_"+menu_id).className = 'item_nonactive';
                }  
            } else {                                                                
                document.getElementById("menuitem_"+i).className = 'item_nonactive';           
            }
        }
    }    
}