Error in Sqlconnection

Question

Hi

can any one help me why is error occured .....?

And i am using conneciton in this way..

SqlConnection con = new SqlConnection(ConfigurationSettings.AppSettings["ConnectionStringNew"]);

Cannot open database "aTestingDB" requested by the login. The login failed.
Login failed for user 'KBBALOCH-PC\KBBALOCH'.

And

I am using dataset and update the dataset column like below and when i call it , it show th updated result in gridview . but it is not updating the database why can nay one help me....?

ds.Tables[0].Rows[9]["name"] = "Khuda bux";