diff --git a/scripts/classes/ProcessInputForm/classShowHideElements.ts b/scripts/classes/ProcessInputForm/classShowHideElements.ts
index 255525a..69cebaf 100644
--- a/scripts/classes/ProcessInputForm/classShowHideElements.ts
+++ b/scripts/classes/ProcessInputForm/classShowHideElements.ts
@@ -6,44 +6,46 @@ export default class classShowHideElements {
    * Show the loading spinner
    * @returns void
    */
-  static showLoadingSpinner(): void  {
-    window.document.getElementById("loadingSpinner").classList.remove("d-none");
+  static showLoadingSpinner(): void {
+    window.document
+      .getElementById("loadingSpinner")
+      ?.classList.remove("d-none");
   }
 
   /**
    * Hide the loading spinner
    * @returns void
    */
-  static hideLoadingSpinner(): void  {
-    window.document.getElementById("loadingSpinner").classList.add("d-none");
+  static hideLoadingSpinner(): void {
+    window.document.getElementById("loadingSpinner")?.classList.add("d-none");
   }
 
   /**
    * Display the table and add animation class
    * @returns void
    */
-  static showDataTable(): void  {
-    window.document.getElementById("tableElement").classList.remove("d-none");
+  static showDataTable(): void {
+    window.document.getElementById("tableElement")?.classList.remove("d-none");
   }
 
   /**
    * Hide the table. Usually caused by an error
    * @returns void
    */
-  static hideDataTable(): void  {
+  static hideDataTable(): void {
     window.document
       .getElementById("tableElement")
-      .classList.add("animate__fadeOut");
+      ?.classList.add("animate__fadeOut");
   }
 
   /**
    * Hide loading spinner and data table
    * @returns void
    */
-  static hideElements(): void  {
+  static hideElements(): void {
     window.document
       .getElementById("tableElement")
-      .classList.add("animate__fadeOut");
-    window.document.getElementById("loadingSpinner").classList.add("d-none");
+      ?.classList.add("animate__fadeOut");
+    window.document.getElementById("loadingSpinner")?.classList.add("d-none");
   }
 }