I have a web page that has coding structured somewhat as follows:

SqlConnection conX =new SqlConnection(blablabla);
conX.Open();
SqlTransaction tran=conX.BeginTransaction();


try{
   SqlCommand cmdInsert =new SqlCommand("INSERT INTO Table1(ColX,ColY) VALUES @x,@y",conX);
   cmdInsert.Transaction=tran;
   cmdInsert.ExecuteNonQuery();

   SqlCommand cmdSelect=new SqlCOmmand("SELECT * FROM Table1",conX);
   cmdSelect.Transaction=tran;
   SqlDataReader dtr=cmdSelect.ExecuteReader();

   //read stuff from dtr
   dtr.Close();

   cmdInsert=new SqlCommand("UPDATE Table2 set ColA=@a",conX);
   cmdInsert.Transaction=tran;
   cmdInsert.ExecuteNonQuery();

   //display MiscMessage
   tran.Commit();
   //display SuccessMessage
}
catch(Exception x)
{
   tran.Rollback();
   //display x.Message
}
finally
{
   conX.Close();
}

So, everything seems to work until MiscMessage. Then, after a while (maybe 15-ish seconds?) x.Message pops up, saying that:

"Timeout expired. The timeout period elapsed prior to completion of the operation or the server is not responding."

So something wrong with my trans.Commit()? The database is not updated so I assume the trans.Rollback works...

I have read that deadlocks can cause timeouts...is this problem cause by my SELECT statement selecting from Table1, which is being used by the first INSERT statement? If so, what should I do? If that ain't the problem, what is?