private void btnRetrieveTestActionPerformed(java.awt.event.ActionEvent evt) {//GEN-FIRST:event_btnRetrieveTestActionPerformed
        // TODO add your handling code here:
        int tid = -1;
        try
        {
            tid = Integer.parseInt(tbxTestID.getText());
        }
        catch(Exception e)
        {
            tid = -1;
        }
        if (tid <= 0)
        {
            tbxError.setText("Invalid test ID.");
            RenderRR(new Test());
            return;
        }
        Test_Controller TC = new Test_Controller("localhost", DBName, DBAccount, DBPwd);
        ArrayList temp = TC.SearchTest(tid, "Test");
        if (temp.size()<=0)
        {
            tbxError.setText(TC.err);
            RenderRR(new Test());
            return;
        }
        tbxError.setText("Current test changed.");
        Test t = (Test)temp.get(0);
        RenderRR(t);
    }