diff --git a/src/main/java/de/hitec/nhplus/treatment/AllTreatmentController.java b/src/main/java/de/hitec/nhplus/treatment/AllTreatmentController.java
index 854c155..117b380 100644
--- a/src/main/java/de/hitec/nhplus/treatment/AllTreatmentController.java
+++ b/src/main/java/de/hitec/nhplus/treatment/AllTreatmentController.java
@@ -186,32 +186,43 @@ public class AllTreatmentController {
 
     @FXML
     public void handleNewTreatment() {
-        try {
-            String selectedPatient = this.comboBoxPatientSelection.getSelectionModel().getSelectedItem();
-            Patient patient = searchInPatientList(selectedPatient);
+        String selectedPatient = this.comboBoxPatientSelection.getSelectionModel().getSelectedItem();
+        Patient patient = searchInPatientList(selectedPatient);
 
-            String selectedNurse = this.comboBoxNurseSelection.getSelectionModel().getSelectedItem();
-            Nurse nurse = searchInNurseList(selectedNurse);
-
-            newTreatmentWindow(patient, nurse);
-        } catch (NullPointerException exception) {
+        if(patient == null) {
             Alert alert = new Alert(Alert.AlertType.INFORMATION);
             alert.setTitle("Information");
             alert.setHeaderText("Patient für die Behandlung fehlt!");
             alert.setContentText("Wählen Sie über die Combobox einen Patienten aus!");
             alert.showAndWait();
+            return;
         }
+
+        String selectedNurse = this.comboBoxNurseSelection.getSelectionModel().getSelectedItem();
+        Nurse nurse = searchInNurseList(selectedNurse);
+
+        if(nurse == null) {
+            Alert alert = new Alert(Alert.AlertType.INFORMATION);
+            alert.setTitle("Information");
+            alert.setHeaderText("Pfleger für die Behandlung fehlt!");
+            alert.setContentText("Wählen Sie über die Combobox einen Pfleger aus!");
+            alert.showAndWait();
+            return;
+        }
+
+        newTreatmentWindow(patient, nurse);
     }
 
     @FXML
     public void handleMouseClick() {
         tableView.setOnMouseClicked(event ->
         {
-            if (event.getClickCount() == 2 && (tableView.getSelectionModel().getSelectedItem() != null)) {
-                int index = this.tableView.getSelectionModel().getSelectedIndex();
-                Treatment treatment = this.treatments.get(index);
-                treatmentWindow(treatment, treatment.getNurse());
+            if (event.getClickCount() != 2 || (tableView.getSelectionModel().getSelectedItem() == null)) {
+                return;
             }
+            int index = this.tableView.getSelectionModel().getSelectedIndex();
+            Treatment treatment = this.treatments.get(index);
+            treatmentWindow(treatment, treatment.getNurse());
         });
     }