求助！！在线等啊；IDispatch error #3902错误

我在用ADO时出现了以下错误：

在

代码为：

void CManageDlg::OnButton2()

{

// TODO: Add your control notification handler code here

m_cmd.CreateInstance("ADODB.Command");

if(!UpdateData())

return;

int nitem=m_ctrllist.GetNextItem(-1,LVNI_SELECTED);

if(nitem==-1)

{

MessageBox("请选择!");

return;

}

if(m_strname.IsEmpty())

{

MessageBox("客户名字不能为空");

return;

}

try

{

int id=atoi(m_ctrllist.GetItemText(nitem,0));

_variant_t vnull;

vnull.vt=VT_ERROR;

vnull.scode=DISP_E_PARAMNOTFOUND;

CString sql;

sql.Format("update CUSTOMER set NAME='%s',ADDR='%s',COMPANY='%s',PHONE='%s' where CUST_ID=%d",m_strname,m_straddr,m_strcompany,m_strphone,id);

m_cmd->ActiveConnection=m_conn;

m_cmd->CommandText=_bstr_t(sql);

m_cmd->Execute(&vnull,&vnull,adCmdText);

m_ctrllist.SetItemText(nitem,1,m_strname);

m_ctrllist.SetItemText(nitem,2,m_straddr);

m_ctrllist.SetItemText(nitem,3,m_strcompany);

m_ctrllist.SetItemText(nitem,4,m_strphone);

UpdateData(false);

// m_cmd.Release();

}

catch(_com_error e)

{

MessageBox(e.ErrorMessage());

}

}

运行时出现IDispatch error #3902的错误提示，

请问怎么解决啊，急！！！！！！！！！1