Alice traveled on an interstate bus to Bolton to get her admission into the degree program at one of the Universities there. Upon reaching the University, she realized that she left her folder containing all her certificates on the bus. She contacted the bus company. With assistance from the bus company, she then contacted the bus driver and asked if he could help to deliver the folder to her. The bus driver made a trip to the University and handed over the folder to her. Alice was very relieved and pleased and instantly announced that she would reward the conductor with $500. 

Once her admission formalities were finalized, Alice realized that she had been too impulsive and now refuses to hand over the reward, saying that there was no agreement as there was no consideration to support her promise. Do you agree? Justify your answer.