Display name which starts with particular character

import javax.swing.*;
class Name1{ 
    public static void main (String arg[]){

        String st=JOptionPane.showInputDialog(null,"Enter any character");
        char ch=st.charAt(0);
        switch(ch){
            case 'a': JOptionPane.showMessageDialog(null,"Ali\n Azam\n Afzal\n");
            break;
            case 'b': JOptionPane.showMessageDialog(null,"Babar\n Bebo\n Bell\n");
            break;
            default: 
                JOptionPane.showMessageDialog(null,"Invalid");
            } 
            } 
            }