title: How to remove all the values in a ComboBox?
body: <pre><code>        rs = statement.executeQuery("select * from user");
  
          while (rs.next()) {
              String username = rs.getString("staffname");
              options1.add(username);    // ObservableList&lt;String&gt; options1 = FXCollections.observableArrayList();
          }
  
          cb.setItems(options1);   // cb is ComboBox object
          cb.setPromptText("Select Your Account");
          cb.setPrefSize(280, 30);
  
          Button bt = new Button("Sign In");
          bt.setFont(Font.font("Calibri", FontWeight.NORMAL, 17));
          bt.setStyle(" -fx-base: #333333;");
          bt.setTextFill(Color.WHITE);
  
          bt.setOnAction(new EventHandler&lt;ActionEvent&gt;() {
              @Override
              public void handle(ActionEvent e) {
                  try {
                      setCenter(userSignin());
  
                  } catch (ClassNotFoundException | SQLException ex) {
                      Logger.getLogger(FrontPage.class.getName()).log(Level.SEVERE, null, ex);
                  }
              }
          });
  </code></pre>
  
  <p>This is my code to read some values from a database and display it in a ComboBox. Now I need to remove all the values in the ComboBox when the Button is pressed. I want to remove all at one click. How can I do it ?</p>