adoquery用参数的有关问题

adoquery用参数的问题
DataModule1->qry->ParamCheck=false;
DataModule1->qry->Parameters->CreateParameter(L"operator_name1", ftString, pdInput, 255, NULL);
DataModule1->qry->Parameters->CreateParameter(L"operator_pwd1", ftString, pdInput, 255, NULL);
DataModule1->qry->Parameters->ParamByName("operator_name1")->Value=edt1->Text.Trim();
DataModule1->qry->Parameters->ParamByName("operator_pwd1")->Value= edt2->Text.Trim();
UnicodeString sql = "select operator_name from [operator] ";
sql = sql + "where operator_name= :operator_name1 ";
sql = sql + "and operator_password= :operator_pwd1 ";
try
{
DataModule1->qry->SQL->Text=sql;
DataModule1->qry->Open();
}
catch(Exception & exception)
{
Application->MessageBox(exception.Message.w_str(), L"数据库错误", MB_OK + MB_ICONSTOP);
return;
}

执行的时候总提示“至少一个参数没有指定值”，可以都指定了啊？

[解决办法]
参数是这样用滴：

C/C++ code

UnicodeString sql = "select operator_name from [operator] "        "where operator_name=:operator_name1 and operator_password=:operator_pwd1";DataModule1->qry->SQL->Text=sql;        DataModule1->qry->Parameters->ParamByName("operator_name1")->Value = edt1->Text.Trim();DataModule1->qry->Parameters->ParamByName("operator_pwd1")->Value = edt2ow