How to take database info while creating dll [Resolved]

Hi all

Im creating dll for each screens in my project .I have a class which contains all database operations. when creating dll for this class im giving database info like this

string strconnection = "Data Source=CLIENT01;Initial Catalog=dbname;User ID=sa;Password=pawd.;";
iam referencing this dll in number of places
but when iam changing the connection info i have to again refer this dll in every where in my project as it is a common dll.
Is there any other methods giving database info in my project so that database class dll refer this location(like appconfig)
how to take value of database info while creating database class dll

Thanks in Advance

[Resolved]