diff --git a/ch32v/lib/calculator.html b/ch32v/lib/calculator.html
index 18297c4..9087ef7 100644
--- a/ch32v/lib/calculator.html
+++ b/ch32v/lib/calculator.html
@@ -79,7 +79,8 @@ function computeTable()
 			"<TABLE BORDER=1>" +
 			"<TR><TD>Goertzel</TD></TR>" +
 			"<TR><TD>Goertzel (Inverse)</TD></TR>" +
-			"</TABLE><TEXTAREA ROWS=6 COLS=120 ID=goertzeloutput></TEXTAREA>";
+			"</TABLE><TEXTAREA ROWS=6 COLS=120 ID=goertzeloutput></TEXTAREA>" +
+			"<P>Click on a ordinal offset to create the C code needed for that tuning parameter. Clicking will copy-to-clipboard.</P>";
 	}
 
 	contents += "<TABLE BORDER=1>";