diff --git a/4.use-case/2.read-a-drivers-license.html b/4.use-case/2.read-a-drivers-license.html
index 959067bc..eac375b3 100644
--- a/4.use-case/2.read-a-drivers-license.html
+++ b/4.use-case/2.read-a-drivers-license.html
@@ -187,6 +187,7 @@ <h1 id='header'>Read A Driver's License <a href="javascript:void(0)" id='readAga
                 resultShowNode.appendChild(createNode("span", "------------------------------"));
                 resultShowNode.appendChild(createNode("br"));
             }
+            document.getElementById('resultAlert_content').innerHTML = "";
             document.getElementById('resultAlert_content').appendChild(resultShowNode);
             document.getElementById('resultAlert').hidden = false;
             document.addEventListener("mousedown", clickToHide);