InfoPath Dev

I have a SharePoint I am trying to populate a repeating table in the form. I keep  getting a Object reference not set to an instance of an object. on the Elements @Start_Postion, @End_Postion, @ Lenght.

I am not sure if I am doing something completely wrong or not.

here is the code i have so far.

XPathNavigator secDSNav = DataSources["File Layout Container"].CreateNavigator();

// Retrieve the rows of the secondary data source

XPathNodeIterator rows = secDSNav.Select(

"/dfs:myFields/dfs:dataFields/dfs:File_Layout_Container", NamespaceManager);

// Loop through the rows of the secondary data source and fill the repating table

while (rows.MoveNext())

{

string FieldName = rows.Current.SelectSingleNode(

"@Field_Name", NamespaceManager).Value;

string DataType = rows.Current.SelectSingleNode(

"@Data_Type", NamespaceManager).Value;

string StartPosition = rows.Current.SelectSingleNode(

"@Start_Position", NamespaceManager).Value;

string EndPosition = rows.Current.SelectSingleNode(

"@End_Position", NamespaceManager).Value;

string Position = rows.Current.SelectSingleNode(

"@Positon", NamespaceManager).Value;

string Length = rows.Current.SelectSingleNode(

"@Length", NamespaceManager).Value;

// Add the item to the repeating table

AddItem(FieldName, DataType, StartPosition, EndPosition, Position, Length);

}

// Remove the first empty item from the repeating table

DeleteFirstEmptyItem();

}

}

 

private void AddItem(string FieldName, string DataType, string StartPosition, string EndPosition, string Position, string Length)

{

XmlDocument doc = new XmlDocument();

XmlNode group = doc.CreateElement("Targeting_Iteration_Recurrence_File_Layout_Fields",

NamespaceManager.LookupNamespace("my"));

XmlNode field = doc.CreateElement("Field_Name_Output_Target",

NamespaceManager.LookupNamespace("my"));XmlNode node = group.AppendChild(field);

node.InnerText = FieldName;

field = doc.CreateElement("Data_Type_Output_Target",

NamespaceManager.LookupNamespace("my"));

node = group.AppendChild(field);

node.InnerText = DataType;

field = doc.CreateElement("Start_Postion_Output_Target",NamespaceManager.LookupNamespace("my"));

node = group.AppendChild(field);

node.InnerText = StartPosition;

field = doc.CreateElement("End_Postion_Output_Target",NamespaceManager.LookupNamespace("my"));

node = group.AppendChild(field);

node.InnerText = EndPosition;

field = doc.CreateElement("Position",NamespaceManager.LookupNamespace("my"));

node = group.AppendChild(field);

node.InnerText = Position;

field = doc.CreateElement("Length_Output_Target",NamespaceManager.LookupNamespace("my"));

node = group.AppendChild(field);

node.InnerText = Length;

doc.AppendChild(group);

MainDataSource.CreateNavigator().SelectSingleNode(

"/my:myFields/my:Section_D_Target_Pop_Req/my:Sub-Section_D6_Output_File_Requirements/my:Preset_Frequency_GRP/my:Recurrence_Frequency/my:Preset_Frequency/my:Targeting_REQ/my:Targeting_Iteration_Recurrence_Additional_File_Layout_Fields",

NamespaceManager).AppendChild(doc.DocumentElement.CreateNavigator());

}

Any help would be great!

Are the Field_Name, Start_Position, etc. attributes direct children of the File_Layout_Container group, or do they belong to another group below that?