Error with onclick function (Snowman)

Hi!
In my game I'm trying to make it so when you press a button, it will print "Your relationship with Frances has improved!" and then add 1 to this value. Below is my javaScript:

<%
s.FRANCES = function(rstatusup) {
	print("Your relationship with Frances has improved!");
	s.FRANCES = rstatusup + 1;
}
s.FRANCES(0);
%>
<button onclick="rstatusup">Flirt with Frances</button>

What this should be doing is, when you click the "Flirt with Frances" button, it should print "Your relationship with Frances has improved!" and also add 1 to the s.FRANCES value. Instead, when I click the button, I get this error:

⚠ Uncaught ReferenceError: rstatusup is not defined (file:///C:/Users/Alec/AppData/Local/Temp/nw5148_20689/index.html#stories/26d38271-fd3c-5baa-24b7-e9da21c5a0fc/test: 1)

Am I doing something wrong or missing some code that is exclusive to Twine? Maybe someone fluent in JavaScript can help?