Datasets - Urgent!!

[Alex]

I have the follow code:

private void crear() {

//creating a dataset

DataSet myDataset=null;
SqlConnection sqlConnection=null;
SqlDataAdapter sqlCommand=null;
try {
//create an instance for a SqlConnection and a Sql Command

sqlConnection = new SqlConnection("server=.; database=JF;
Trusted_Connection=false; uid=sa; pwd=; Pooling=true;");
sqlCommand = new SqlDataAdapter("select
cantidad,concepto,prec_unit,valor_venta from fact_detalle",sqlConnection);
myDataset = new DataSet();

//mark the command as a text
sqlCommand.SelectCommand.CommandType = CommandType.Text;

//open the connection and execute
sqlConnection.Open();
sqlCommand.Fill(myDataset);

}
catch {
throw;
}
finally {
if(sqlConnection!=null)
sqlConnection.Close();
// MessageBox.Show("The connection is close");
}
// return myDataset;

dataGrid1.DataSource=myDataset.Tables[0];
}
private void nueva_fila()

{
DataRow anyRow = myDataset.Tables[0].NewRow();
}
---------------------------------
on nueva_fila there´s an error , when compila the "myDataset" is underlined
and the follow task is shown:

The type or namespace name 'myDataset' could not be found (are you missing a
using directive or an assembly reference?)
---
Why?, it´s because the first void is private.... please help me

[FrankieNocturne]

The variable myDataset declared in the private function crear will only
exist in that function. If other function such as nueva_fila() want to
access it, it has to be a member variable, i.e. declared in the class.

Hope this help.

Best regards,
Frankie Leung.