private void getBranch(){
        try{
            String sql = "select branch from BranchList";
            pst = conn.prepareStatement(sql);
            rs = pst.executeQuery();
            branch.addItem("");
            while(rs.next()){
                branchList.add(rs.getString("branch"));
            }
            
        }
        catch(Exception e){
            JOptionPane.showMessageDialog(null, e);
        }
        finally{
            if(pst!=null){
                try{
                    pst.close();
                }
                catch(SQLException e){
                    
                }
            }
            if(rs!=null){
                try{
                    rs.close();
                }
                catch(SQLException e){
                    
                }
            }
        }
    }