当按下删除按钮时，没有从一个或多个参数给出值

当前我正在做的是选择一个数据从MsDatabase和字符串后

query = "delete from RegisterItem where  Name =" +txtName1.Text+""; 

它显示了一个错误，说一个或多个参数没有给出值，而我已经检查了txtName1是否匹配Name

{
    OleDbConnection connect = new OleDbConnection();
    public MenClothing(string text)
    {
        InitializeComponent();
        txtUsername.Text = text;
        connect.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:'Users'Teronkee'Desktop'OFFICAL STAC'StacProductions'DatabaseSaveItem.accdb";
    }
    public MenClothing()
    {
        InitializeComponent();

        connect.ConnectionString = @"Provider=Microsoft.ACE.OLEDB.12.0;Data Source=C:'Users'Teronkee'Desktop'OFFICAL STAC'StacProductions'DatabaseSaveItem.accdb";

    }

    private int upperCase(string pass)
    {
        int num = 0;
        foreach (char ch in pass)
        {
            if (char.IsUpper(ch))
            {
                num++;
            }
        }
        return num;
    }
    private void btnlogout_Click(object sender, EventArgs e)
    {
        this.Hide();
        Form2 Return = new Form2(txtUsername.Text);
        Return.ShowDialog();
    }
    private void MenClothing_Load(object sender, EventArgs e)
    {
        try
        {
            connect.Open();
            OleDbCommand command = new OleDbCommand();
            command.Connection = connect;
            string query = "select * from RegisterItem";
            command.CommandText = query;
            OleDbDataReader reader = command.ExecuteReader();
            while (reader.Read())
            {
                comboBox1.Items.Add(reader["Name"].ToString());
            }
            connect.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error " + ex);
        }
        connect.Close();
    }
    private void pictureBox1_Click(object sender, EventArgs e)
    {
        pictureBox1.ImageLocation = ItemUrl.Text;
    }
    private void textBox1_TextChanged(object sender, EventArgs e)
    {
        pictureBox1.ImageLocation = ItemUrl.Text;
    }
    private void button1_Click(object sender, EventArgs e)
    {
        try { 
        connect.Open();
        OleDbCommand command = new OleDbCommand();
        command.Connection = connect;
        command.CommandText = "insert into RegisterItem([Name], [Url],[Description], [Price]) values('" + ItemName.Text + "','" + ItemUrl.Text + "','" + ItemDescription.Text + "','" + ItemPrice.Text + "')";
            string str = ItemUrl.Text;
            pictureBox1.ImageLocation = str;
            string str1 = textBox1.Text;
            Image img = Image.FromFile(str);
            pictureBox1.Image = img;
            command.ExecuteNonQuery();
            MessageBox.Show("Data Saved");
            txtID1.Text = txtUsername.Text;
                txtName1.Text = ItemName.Text;
                txtDescription1.Text = ItemDescription.Text;
               txtPrice1.Text = ItemPrice.Text;
               ItemName.Text = "";
              ItemDescription.Text = "";
                ItemPrice.Text = "";
            connect.Close();
        }
        catch (Exception ex)
        {
        MessageBox.Show("Error " +ex);
        }
        connect.Close();
    }
    private void label5_Click(object sender, EventArgs e)
    {
    }
    private void textBox2_TextChanged(object sender, EventArgs e)
    {
    }
    private void textBox5_TextChanged(object sender, EventArgs e)
    {
    }
    private void btnDelete_Click(object sender, EventArgs e)
    {
        try
        {
            connect.Open();
            OleDbCommand command = new OleDbCommand();
            command.Connection = connect;
            string query = "delete from RegisterItem where  Name ="                    +txtName1.Text+"";
            command.CommandText = query;

            command.ExecuteNonQuery();
            MessageBox.Show("Data deleted ");
            connect.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error " + ex);
        }
        connect.Close();
        //if (txtUsername.Text == txtID1.Text)
        //   { 
        //   txtName1.Text = "";
        //    txtDescription1.Text = "";
        //    txtPrice1.Text = "";
        //  }
    }
    private void ItemDescription_TextChanged(object sender, EventArgs e)
    {
    }
    private void AddString_Click(object sender, EventArgs e)
    {
        string namestr = txtName1.Text;
        comboBox1.Items.Add(namestr);
    }
    private void comboBox1_SelectedIndexChanged(object sender, EventArgs e)
    {
        try
        { 
            connect.Open();
            OleDbCommand command = new OleDbCommand();
            command.Connection = connect;
            string query = "select * from RegisterItem where Name='" + comboBox1.Text + "'";
            command.CommandText = query;
            OleDbDataReader reader = command.ExecuteReader();
            while (reader.Read())
            {

                txtName1.Text = reader["Name"].ToString();
                txtDescription1.Text = reader["Description"].ToString();
                txtPrice1.Text = reader["Price"].ToString();
            }
            connect.Close();
        }
        catch (Exception ex)
        {
            MessageBox.Show("Error " + ex);
        }
        connect.Close();
    }
}

}