Enterprise Library3.1 for dataaccess

Question

Hi,

I am writing a class using Class library template.I am using Enterprise library 3.1 for Dataaccess.
But when I am calling the methods of class from a client application,It is giving some error saying that the connection name is not defined in configuration file,though I have defined the connection string..I have tried very much but the same error occurs again and again..plzz some body help me.

thanks,