diff --git a/examples/demo-instructions.html b/examples/demos/demo_1.html
similarity index 100%
rename from examples/demo-instructions.html
rename to examples/demos/demo_1.html
diff --git a/examples/demos/demo_2.html b/examples/demos/demo_2.html
new file mode 100644
index 00000000..0613ee3e
--- /dev/null
+++ b/examples/demos/demo_2.html
@@ -0,0 +1,43 @@
+<!DOCTYPE html>
+<html>
+<head>
+	<script src="../jspsych.js"></script>
+	<script src="../plugins/jspsych-image-keyboard-response.js"></script>
+	<link rel="stylesheet" href="../css/jspsych.css"></link>
+	<style>
+		img {
+			width: 300px;
+		}
+	</style>
+</head>
+<body>
+</body>
+<script>
+	var trial_1 = {
+		type: "image-keyboard-response",
+		stimulus: 'img/happy_face_1.jpg',
+		choices: [89, 78],
+		prompt: '<p class="center-content">Is this face happy? Y or N.</p>'
+  }
+
+  var trial_2 = {
+    type: 'image-keyboard-response',
+    stimulus: 'img/sad_face_2.jpg',
+    choices: [89, 78], // Y or N
+    prompt: '<p class="center-content">Is this face happy? Y or N.</p>'
+  }
+
+  var trial_3 = {
+    type: 'image-keyboard-response',
+    stimulus: 'img/happy_face_2.jpg',
+    choices: [89, 78], // Y or N
+    prompt: '<p class="center-content">Is this face happy? Y or N.</p>',
+  }
+
+
+  jsPsych.init({
+    timeline: [trial_1, trial_2, trial_3],
+    default_iti: 250
+  });
+</script>
+</html>
\ No newline at end of file
diff --git a/examples/demo-flanker-demo.html b/examples/demos/demo_3.html
similarity index 100%
rename from examples/demo-flanker-demo.html
rename to examples/demos/demo_3.html
diff --git a/plugins/jspsych-call-function.js b/plugins/jspsych-call-function.js
index 93b0d793..ae329dae 100644
--- a/plugins/jspsych-call-function.js
+++ b/plugins/jspsych-call-function.js
@@ -21,20 +21,11 @@ jsPsych.plugins['call-function'] = (function() {
         no_function: false,
         description: ''
       },
-      // a rare case where we override the default experiment level
-      // value of this parameter, since this plugin should be invisible
-      // to the subject of the experiment
-      post_trial_gap: {
-        type: jsPsych.plugins.parameterType.INT,
-        default: 0,
-        no_function: false,
-        description: ''
-      }
     }
   }
 
   plugin.trial = function(display_element, trial) {
-
+    trial.post_trial_gap = 0;
     var return_val = trial.func();
 
     var trial_data = {
diff --git a/plugins/jspsych-external-html.js b/plugins/jspsych-external-html.js
index fba43bcd..4683480b 100644
--- a/plugins/jspsych-external-html.js
+++ b/plugins/jspsych-external-html.js
@@ -34,7 +34,7 @@ jsPsych.plugins['external-html'] = (function() {
       },
       check_fn: {
         type: jsPsych.plugins.parameterType.FUNCTION,
-        default: 'function() { return true; }',
+        default: function() { return true; },
         no_function: false,
         description: ''
       },
