Cannot Convert Type

[Memnoch1207]

Error Message:

DatabaseClass.cs(102,12): error CS0029: Cannot implicitly convert type 'System.Data.DataSet' to 'System.Data.SqlClient.SqlDataReader'

public DataSet db_query(string SqlStatement, bool isStoredProc)
	{
		DataSet dSet = new DataSet();

		try
		{
			if(SqlStatement == "")
			{
				MessageBox.Show("SQL Statment is empty.");
			}
			
			if(isStoredProc == true)
			{
				String strQuery = "EXEC " + SqlStatement.Trim();
				SqlDataAdapter sAdapter = new SqlDataAdapter(strQuery,myConnection);
				sAdapter.Fill(dSet,SqlStatement);
			}
			else
			{
				string strQuery = SqlStatement.Trim();
				SqlDataAdapter sAdapter = new SqlDataAdapter(strQuery,myConnection);
				sAdapter.Fill(dSet,SqlStatement);
			}
		}
		catch(Exception exp)
		{
			MessageBox.Show("Error fetching records for the query:- " + SqlStatement + ". Possible cause:- " + exp.ToString() );
		}	
				
		return(dSet);
	}

public static void Main()
	{
		string myConnectionString = ("server=localhost;database=pubs;user id=steve;password=jensen;");
		Database myDB = new Database();
		SqlDataReader reader;
		
		
		db_open(myConnectionString); 
		reader = myDB.db_query("SELECT * FROM authors", false);
		
		while(reader.Read()) 
	   {
		  Console.WriteLine(reader["au_lname"]);
	   }
		
		db_close();
	}

Obviously the issue is in reader = myDB.db_query, since db_query returns a DataSet and I am trying to read the returned DataSet with the SqlReader...Any ideas on how to do this???