Help pleas

In my program I have this code:

string SqlString = "INSERT INTO WordTbl ( Word, WordDefinition ) VALUES ('" + WordTxt.Text.Trim() + "','" + DefinitionTxt.Text.Trim()+ "')";

MyConnection.Open ();
MyConnection.CreateCommand().CommandText= SqlString;

MyConnection.Close ();

I have Access db with free columns, that one of them (Auto number )
After this code no rows created,
What can be a problem?
Thank you

Балшое балшое СПОСИБО