diff --git a/web/src/app/js/base.js b/web/src/app/js/base.js
index 7f8516c..e3f844c 100644
--- a/web/src/app/js/base.js
+++ b/web/src/app/js/base.js
@@ -121,6 +121,15 @@ function loadScript(id, file, cback) {
 function getNormalizedURI() { return window.location.pathname.replace(/\/+?$/, '') }
 function capitalize(s) { return s.charAt(0).toUpperCase() + s.substr(1) }
 function sleep(ms) { return new Promise(resolve => setTimeout(resolve, ms)) }
+async function waitUntil(cback, secs) {
+	var i = 0;
+	while (i < secs) {
+		if (cback())
+			return;
+		await sleep(1000);
+		i++;
+	}
+}
 
 function s(name) {
 	if (app.strings === undefined || !name.match(/^[a-zA-Z0-9\.\_]+$/))