// Function aimed to ping the webhttrack server regularly to keep it alive // If the browser window is closed, the server will eventually shutdown function ping_server() { var iframe = document.getElementById('pingiframe'); if (iframe && iframe.src) { iframe.src = iframe.src; setTimeout(ping_server, 30000); } } // Create an invisible iframe to hold the server ping result // Only modern browsers will support that, but old browsers are compatible // with the legacy "wait for browser PID" mode if (document && document.createElement && document.body && document.body.appendChild && document.getElementById) { var iframe = document.createElement('iframe'); if (iframe) { iframe.id = 'pingiframe'; iframe.style.display = "none"; iframe.style.visibility = "hidden"; iframe.width = iframe.height = 0; iframe.src = "/ping"; document.body.appendChild(iframe); ping_server(); } }