How to populate a label with average value from MSSQL in ASP.NET using stored procedures?

See more:

C#

ASP.NET

SQL

I'm having problem populating a Label with average value from MSSQL database.
The code written in database is this:

ALTER PROCEDURE [dbo].procTakeAverage

(
@ID_Person int


)
AS
	BEGIN
	SELECT AVG (RATING.Grade) from RATING
	inner join SUBJECT on SUBJECT.ID_Subject= RATING.ID_Subject
	where RATING.ID_Subject = @ID_Person and RATING.ID_RatingType=1
	END

This stored procedure works perfectly and returns the average value.
The problem is how to show this value in a Label using ASP.NET technology (code).

This is what I tried so far.

What I have tried:

<pre><pre lang="c#">

public void AverageValue()
{
string average= String.Empty;
DataTable dt = new DataTable();
SqlConnection sqlConn = new SqlConnection("Here is the string connection");


try
{
sqlConn.Open();

SqlCommand sqlCmd = new SqlCommand("procTakeAverage", sqlConn);


sqlCmd.CommandType = CommandType.StoredProcedure;


sqlCmd.Parameters.Add("@ID_Person", SqlDbType.Int).Value = average;


sqlCmd.Parameters["@ID_Person"].Value = Convert.ToInt32(lblID_Nxenesi.Text);

sqlCmd.ExecuteNonQuery();
average = lblAverage.Text.ToString();

sqlConn.Close();

}
catch { }

}

This code is not showing me the average value in lblAverage.

Thank you in advance for your time.
Cheers.