diff --git a/web/javascript/common.js b/web/javascript/common.js
index c2e1a70c7..edf60a015 100644
--- a/web/javascript/common.js
+++ b/web/javascript/common.js
@@ -97,6 +97,9 @@ Array.prototype.clone = function () {
  */
 function setInnerHTML( e, html )
 {
+	if( e == undefined )
+		return;
+
 	/* innerHTML is listed as a string, but the browser seems to change it.
 	 * For example, "∞" gets changed to "∞" somewhere down the line.
 	 * So, let's use an arbitrary  different field to test our state... */