厦门同安博爱医院:C#错误提示未提供该参数

protected int GetID()
{
SqlConnection MyConn = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionString"].ToString());
SqlCommand MyCommand = new SqlCommand();
MyCommand.Connection = MyConn;
MyConn.Open();
int ID = 0;
try
{

MyCommand.CommandText = "select * from tbl_bigclass where id="+Request["id"];
ID = System.Convert.ToInt32(MyCommand.ExecuteScalar().ToString())+1;

}
catch
{
ID = 0;
}
MyConn.Close();
return ID;

}
private void Button1_Click(object sender, System.EventArgs e)
{
string Add_username = null;
this.lbl_errors.Visible = true;
if (this.txt_admin.Text.Trim() == "")
{
this.lbl_errors.Text = "添加失败，你没有输入用户名,请返回！<br>";
this.lbl_errors.ForeColor = System.Drawing.Color.Red;
return;
}
int ID = this.GetID();
Add_username = this.txt_admin.Text.Trim();
this.sqlUpdateCommand1.CommandText = "UPDATE tbl_bigclass SET BigClassName = Add_username WHERE id =ID";
this.sqlUpdateCommand1.Parameters["@ID"].Value = ID;
this.sqlUpdateCommand1.Parameters["@BigClassName"].Value = Add_username;
this.sqlUpdateCommand1.Parameters["@classid1"].Value = ID;
this.sqlUpdateCommand1.Connection = this.sqlConnection1;
this.sqlConnection1.Open();
//
//try
//{
this.sqlUpdateCommand1.ExecuteNonQuery();
this.lbl_errors.Text = "添加成功，请返回！<br>";
this.lbl_errors.ForeColor = System.Drawing.Color.Red;

//}
//catch
//{
//this.lbl_errors.Text = "添加失败，请返回重试！<br>";
//this.lbl_errors.ForeColor = System.Drawing.Color.Red;
//}
this.sqlConnection1.Close();

this.txt_admin.Text = "";
}
}
System.Data.SqlClient.SqlException: 被准备语句 '(@id int,@BigClassName nvarchar(50),@classid1 int,@Original_id i' 需要参数 @Original_id，但未提供该参数。