Null reference exception when trying to use DataAdapter Update

[webbsk]

I keep getting an exception when I call the DataAdapter Update method.
I have been trying to figure out what is causing the null reference
exception for this code for what seems like forever:

private void DoInserts(OdbcD ataAdapter odbcDataAdapter , string
tableName)
{
DataTable dataTableChange d =

dsTapes.Tables[tableName].GetChanges(Dat aRowState.Added );

if ((dataTableChan ged != null) &&
(dataTableChang ed.Rows.Count 0))
{
// Open the connection if its not already open.
if (odbcConnection .State !=
System.Data.Con nectionState.Op en)
{
odbcConnection. Open();
}

//Create a new transaction.
odbcDataAdapter .InsertCommand. Transaction =
odbcConnection. BeginTransactio n();

try
{
//Submit the changes.
odbcDataAdapter .Update(dsTapes ,
dataTableChange d.TableName.ToS tring());
//Commit the changes and close the connection.
odbcDataAdapter .InsertCommand. Transaction.Com mit();
}
catch (Exception ex)
{

odbcDataAdapter .InsertCommand. Transaction.Rol lback();
throw (ex);
}
}
}

The exception information has not been helpful. All it says is: "Object
reference not set to an instance of an object."

I don't know if this will help, but the Insert command looks like this:

tapeLogInsert = odbcConnection. CreateCommand() ;
tapeLogInsert.C ommandText =
"INSERT INTO " + tapeLogODBCName .Trim()
+ " (NBR, Backup_Name, BakDate, ScrDate, Location, "
+ "Tape_No, Tape_Set, Usage, Comment, UseDate) "
+ "VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?)";
tapeLogInsert.P arameters.Add(n ew OdbcParameter(" NBR",
OdbcType.Int));
tapeLogInsert.P arameters["NBR"].SourceColumn = "nbr";
tapeLogInsert.P arameters.Add(" Backup_Name", OdbcType.Char, 17,
"backup_nam e");
tapeLogInsert.P arameters.Add(n ew OdbcParameter(" BakDate",
OdbcType.DateTi me));
tapeLogInsert.P arameters["BakDate"].SourceColumn = "bakdate";
tapeLogInsert.P arameters.Add(n ew OdbcParameter(" ScrDate",
OdbcType.DateTi me));
tapeLogInsert.P arameters["ScrDate"].SourceColumn = "scrdate";
tapeLogInsert.P arameters.Add(" Location", OdbcType.Char, 1,
"location") ;
tapeLogInsert.P arameters.Add(n ew OdbcParameter(" Tape_No",
OdbcType.SmallI nt));
tapeLogInsert.P arameters["Tape_No"].SourceColumn = "tape_no";
tapeLogInsert.P arameters.Add(n ew OdbcParameter(" Tape_Set",
OdbcType.SmallI nt));
tapeLogInsert.P arameters["Tape_Set"].SourceColumn = "tape_set";
tapeLogInsert.P arameters.Add(n ew OdbcParameter(" Usage",
OdbcType.SmallI nt));
tapeLogInsert.P arameters["Usage"].SourceColumn = "usage";
tapeLogInsert.P arameters.Add(" Comment", OdbcType.VarCha r, 50,
"comment");
tapeLogInsert.P arameters.Add(n ew OdbcParameter(" UseDate",
OdbcType.DateTi me));
tapeLogInsert.P arameters["UseDate"].SourceColumn = "usedate";
tapeLogAdapter. InsertCommand = tapeLogInsert;

Does any one have any idea what is going on here or how to go about
finding out? Any suggestions would be appreciated: I don't even know
how to figure out which reference is null!