if  (textBox2.Text != textBox3.Text)
            {
                MessageBox.Show("确认密码错误！","提示",MessageBoxButtons .OK ,MessageBoxIcon.Warning );
            }
            else if (textBox1.Text !=txtPwd.Text )
                 {
                MessageBox.Show("旧密码确认错误！","提示",MessageBoxButtons .OK ,MessageBoxIcon.Warning );
            }
            else
            {
                SqlDataAdapter mydr=new SqlDataAdapter ();
                SqlCommand com = new SqlCommand("update LoginTable set LoginPwd=@LoginPwd where Username=@Username");
                com.Parameters.AddWithValue("@LoginPwd", textBox3.Text);
                mydr.UpdateCommand = com;
                mydr.UpdateCommand.ExecuteNonQuery();
                MessageBox.Show("修改成功！", "提示", MessageBoxButtons.OK, MessageBoxIcon.Warning);
                this.Close();
这是我的代码  不知道哪里出错了  该怎么修改~~高手求解。。。。

运了  说我的txtpwd不存在  因为我的这个txtpwd是在登陆的那张表里的  似乎没调用还是怎么搞的  我不明白了

这个  怎么发啊