Honesty, a safe policy

One the other day , i had gone to a music store to buy a blank CD. Unfortunately, the shopkeeper did not have any change for the Tk 500 note that i gave him. So he politely apologized and asked me to wait while one of his boys ran out to get the change, science he could not find any . the shopkeeper then told me that i could come back without the change. since he could not find any. The shopkeeper then told me that i could come back later and give him to keep my address and contact number, the shopkeeper just smiled and said that it was not necessary. I did not return  next day, But went back only after a week or so . Upon entering the shop to return the money, the shopkeeper gave me a big smile and even gave a sigh of relief upon seeing me . i guess he thought it was worth trusting my honesty, which was showing on his glowing smile while taking the money from my hand!