AddSourceDialog.fxml

<?xml version="1.0" encoding="UTF-8"?>

<?import javafx.scene.control.Button?>
<?import javafx.scene.control.ComboBox?>
<?import javafx.scene.layout.AnchorPane?>

<AnchorPane id="AnchorPane" prefHeight="139.0" prefWidth="369.0" xmlns="http://javafx.com/javafx/8.0.111" xmlns:fx="http://javafx.com/fxml/1" fx:controller="joanakeygui.AddSourceDialogController">
   <children>
      <ComboBox fx:id="selectMethodCB" layoutX="14.0" layoutY="14.0" prefHeight="26.0" prefWidth="341.0" promptText="select by which method you want to select " />
      <ComboBox fx:id="selectionCB" layoutX="14.0" layoutY="61.0" prefHeight="26.0" prefWidth="341.0" promptText="select " />
      <Button layoutX="14.0" layoutY="99.0" mnemonicParsing="false" prefHeight="26.0" prefWidth="58.0" text="Ok" onAction="#onOk"/>
      <Button layoutX="86.0" layoutY="99.0" mnemonicParsing="false" prefHeight="26.0" prefWidth="58.0" text="Cancel" />
   </children>
</AnchorPane>