Combo with ObservableMap Binding

I have a Combo populated using ObservableMap. What i want is if an item(key) is selected in combo, to be able to get corresponding object(value). This is what i have so far

import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.HashMap;
import java.util.logging.Level;
import javafx.application.Application;
import javafx.collections.FXCollections;
import javafx.collections.ObservableList;
import javafx.collections.ObservableMap;
import javafx.scene.Scene;
import javafx.scene.control.ComboBox;
import javafx.scene.layout.BorderPane;
import javafx.stage.Stage;
import org.controlsfx.control.textfield.TextFields;

public class ComboWithHashMap extends Application{
    private ComboBox autocompleteCombo = new ComboBox();
    private ObservableMap<String, Member> list;
    public static void main(String[] args) {
       launch(args);
   }

@Override
public void start(Stage primaryStage) throws Exception {
    primaryStage.setTitle("Combo Sample");
    primaryStage.setWidth(450);
    primaryStage.setHeight(550);

    list = FXCollections.observableMap(getActiveMember());
    autocompleteCombo.getItems().setAll(list.keySet());
    TextFields.bindAutoCompletion(autocompleteCombo.getEditor(), autocompleteCombo.getItems());
    Scene scene = new Scene(new BorderPane(autocompleteCombo), 880, 600);
    primaryStage.setScene(scene);
    primaryStage.show();
}


public HashMap<String, Member> getActiveMember(){
    HashMap<String, Member> map = new HashMap<String, Member>();
    Member member1 = new Member(1, "123", "John Doe");
    Member member2 = new Member(1, "234", "Sally Doe");
    Member member3 = new Member(1, "345", "Billy Doe");

    map.put( member1.getMilkNo(), member1);
    map.put( member2.getMilkNo(), member2);
    map.put( member3.getMilkNo(), member3);

    return map;
}

public class Member {
private int id;
private String milkNo;
private String fullName;

public Member(int id, String milkNo, String fullName) {
    this.id = id;
    this.milkNo = milkNo;
    this.fullName = fullName;
}

public int getId() {
    return id;
}

public void setId(int id) {
    this.id = id;
}


public String getMilkNo() {
    return milkNo;
}

public void setMilkNo(String milkNo) {
    this.milkNo = milkNo;
}

@Override
public String toString() {
    return fullName;
}

 }

}

The problem is so far i cannot get the corresponding object(value) when a key is selected.