iam getting error in group by condition in ado.net

[developerit]

hi, iam using asp.net with c# when iam trying to execute this querry iam getting error can you correct my querry

SqlCommand cmdallltransactions = new SqlCommand("SELECT SUM(Amount)FROM AllTransactions WHERE (TransCode <> 0) GROUP by BranchKey="+Convert.ToInt32(Session["BranchKey"])+"", con);
con.Open();
txttotal.Text = Convert.ToString(Convert.ToInt32(cmdallltransactions.ExecuteScalar()));
con.Close();

error iam getting is Incorrect syntax near '='.

[i j russell]

SELECT SUM(Amount)
FROM AllTransactions
WHERE (TransCode <> 0)
AND BranchKey = 'branchkey'

You should also look at parameterizing your query.