Add file input change event handler to reset message sections

sage_validation/file_validator/templates/upload.html

@@ -126,5 +126,20 @@
                 submitBtn.disabled = false;
             }
         });
+        document.getElementById('fileInput').addEventListener('change', function () {
+            const errorSection = document.getElementById('errorSection');
+            const successSection = document.getElementById('successSection');
+            const downloadSection = document.getElementById('downloadSection');
+            const errorList = document.getElementById('errorList');
+            const successMessage = document.getElementById('successMessage');
+
+            // Hide previous messages and download button
+            errorSection.classList.add('hidden');
+            successSection.classList.add('hidden');
+            downloadSection.classList.add('hidden');
+            // Clear contents
+            errorList.innerHTML = '';
+            successMessage.innerHTML = '';
+        });
     </script>
 {% endblock %}
\ No newline at end of file