Set Auto-Increment into previous value JAVA PreparedStatement MYSQL

I have 3 buttons (add, save, cancel). If I press the add button, it automatically generates an auto-incremented value and is displayed in a text field. If I press the save button, it updates the record. My problem is when I press the cancel button, I want to be able to delete the current data added and set the auto-increment key to the primary key of the deleted data. Is it possible to do this?

dc.connect();
          try {
          PreparedStatement st=dc.getConnection().prepareStatement("Delete from Employeemaster where empno = '" + empno.getText() + "'");
          i=st.executeUpdate();
          if (i>0) {
            dc.getConnection().commit();


        }
    } catch (Exception e) {
        JOptionPane msg=new JOptionPane();
        msg.showMess开发者_如何学PythonageDialog(this,"Database Error: "+e.getMessage());
    }

    dc.disconnect();
    dc.connect();
          try {
          PreparedStatement st=dc.getConnection().prepareStatement("ALTER TABLE employeemaster AUTO_INCREMENT ='" + empno.getText() + "'");
          i=st.executeUpdate();
          if (i>0) {
            dc.getConnection().commit();


        }
    } catch (Exception e) {
        JOptionPane msg=new JOptionPane();
        msg.showMessageDialog(this,"Database Error: "+e.getMessage());
    }

I tried replacing

ALTER TABLE employeemaster AUTO_INCREMENT ='" + empno.getText() + "'" 

into

ALTER TABLE employeemaster AUTO_INCREMENT = 10003; 

and it worked. Is it possible to set the auto-incremented value to the one contained/entered in a textfield?

Additional info: The error I get is

"You have an error in your SQL syntax; check the manual that corresponds to your MYSQL server version for the right syntax to use near "10003" at line 1."

The use of single quote will cause mysql cast the auto_increment value (integer) into string, which is not desirable

Strip the single quote, like

"ALTER TABLE employeemaster AUTO_INCREMENT=" + empno.getText()

Or

cast empno.getText() into integer