SubSonic Transaction

Hi all I'm trying to perform a transaction where there are two updates on the same table and one insert to another table. Here is the code that I've written :

List<SubSonic.SqlQuery> coll = new List<SubSonic.SqlQuery>();
coll.Add(new SubSonic.Update(WestsideBank.CustomerAccount.Schema).Set(WestsideBank.CustomerAccount.BalanceColumn).EqualTo(ChangedDesBalance).Where(WestsideBank.CustomerAccount.AccountIDColumn).IsEqualTo(desacid));
coll.Add(new SubSonic.Update(WestsideBank.CustomerAccount.Schema).Set(WestsideBank.CustomerAccount.BalanceColumn).EqualTo(ChangedSrcBalance).Where(WestsideBank.CustomerAccount.AccountIDColumn).IsEqualTo(srcacid));
coll.Add(new SubSonic.Insert().Into(WestsideBank.Transaction.Schema).Values("newid()", srcacid, amttrans, "getdate()", desacid, ChangedSrcBalance));
SubSonic.SqlQuery.ExecuteTransaction(coll);

Now this code is giving me an error saying that

1.Error 1 The best overloaded method match for 'System.Collections.Generic.List<SubSonic.SqlQuery>.Add(SubSonic.SqlQuery)' has some invalid arguments C:\Inetpub\wwwroot\WestsideBank\Customers\Transfers.aspx.cs 41 

2.Error 2 Argument '1': cannot convert from 'SubSonic.Insert' to 'SubSonic.SqlQuery' C:\Inetpub\wwwroot\WestsideBank\Customers\Transfers.aspx.cs 41 

Now I think that my choice of "type class" here is wrong but what should I use to support both insert and update? Or is there any other better way of doing it.

Also I used sql "newid()" and "getdate()"  inside the insert statement. Is it the right way to do it or is there any subsonic special function which does this for me. And also should I use quotes for variables that I use inside the "insert()" parameter. Please help.

To do this you can't se the helper methods

http://subsonicproject.com/active-record/transactions/

Thanks man. That page was exceptionally helpfull. But one thing I did not understand is that

coll.Add(p1.GetUpdateCommand(Environment.UserName));

coll.Add(p2.GetUpdateCommand(Environment.UserName));

What is with environment.username? What is that? What is its purpose.

http://msdn.microsoft.com/en-us/library/system.environment.username.aspx

It is then name of the logged in user to the system