String id = (String) cbName.getSelectedItem();
String strid = id.replaceAll("\\D+", ""); //remove all chars excep number

//set id for action delet and update
etIdStudentUpdate.setText(strid);
etIdStudentDelete.setText(strid);

//show data by id
DatabaseFunctions df = new DatabaseFunctions();
df.getConnection();
df.showDataByID(etNameUpdate, etMajorsUpdate, strid);