from错误求帮忙改下啊

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;
using System.Data.OleDb;

namespace 专科医院门诊系统_眼科_
{

public partial class 主界面 : Form
{
    OleDbDataAdapter adapter;
    DataTable table = new DataTable();
    string str = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=E:\design\vc\project\专科医院门诊系统（眼科）\db1.accdb";
    OleDbConnection con = new OleDbConnection();
    public 主界面()
    {
        InitializeComponent();
        button1.Click += new EventHandler(button1_Click);
        button2.Click += new EventHandler(button2_Click);
    }
    private void textbox1_TextChanged(object sender, EventArgs e)
    {
    }
    private void textbox2_TextChanged(object sender, EventArgs e)
    {
    }
    private void radioButton1_Checked(object sender, EventArgs e)
    {
    }
    private void radioButton2_Checked(object sender, EventArgs e)
    {
    }
    private void radioButton3_Checked(object sender, EventArgs e)
    {
    }
    private void radioButton4_Checked(object sender, EventArgs e)
    {
    }
    private void button1_Click(object sender, EventArgs e)
    {
        if (textbox1.Text != "" && textbox2.Text != "")
        {
            string sql = "select * from user where ID=" + textbox1.Text + " and [password]='" + textbox2.Text + "'";
            adapter = new OleDbDataAdapter(sql, str);
            OleDbCommandBuilder buider = new OleDbCommandBuilder(adapter);
            adapter.InsertCommand = buider.GetInsertCommand();
            table.Clear();
            adapter.Fill(table);
            if (table.Rows.Count > 0)
            {
                Form f3 = new Form3();
                f3.Show();
                this.Hide();
            }
            else
            {
                MessageBox.Show("用户名或密码不能空");
            }

        }
        if (radioButton1.Checked == true)
        {
            this.Hide();
            new 医生调取就诊号界面().ShowDialog();
        }
        else if (radioButton2.Checked == true)
        {
            this.Hide();
            new 挂号缴费选择界面().ShowDialog();
        }
        else if (radioButton3.Checked == true)
        {
            this.Hide();
            new 药房人员调取就诊号界面().ShowDialog();
        }
        else if (radioButton4.Checked == true)
        {
            this.Hide();
            new 医导查询界面().ShowDialog();
        }
    }
    private void button2_Click(object sender, EventArgs e)
    {
        textbox1.Text = textbox2.Text = string.Empty;
    }

    private void 主界面_Load(object sender, EventArgs e)
    {

    }


}

}

user是关键字，加上方括号
[user]

你的界面是什么样的？按了按钮了么？
if (radioButton1.Checked == true)有没有走到

我给你看下我的界面和 access啊 截图给你

form3是什么

    if (radioButton1.Checked == true)
    {
        this.Hide();
        new 医生调取就诊号界面().ShowDialog();
    }
    else if (radioButton2.Checked == true)
    {
        this.Hide();
        new 挂号缴费选择界面().ShowDialog();
    }
    else if (radioButton3.Checked == true)
    {
        this.Hide();
        new 药房人员调取就诊号界面().ShowDialog();
    }
    else if (radioButton4.Checked == true)
    {
        this.Hide();
        new 医导查询界面().ShowDialog();
    }
            看上去这些应该塞在
                        if (table.Rows.Count > 0)
        {
            Form f3 = new Form3();
            f3.Show();
            this.Hide();
        }
                    这个里面