Connection String

Question

I have developed a web application using linq. i connected my database with using wizard of Linq to Sql classes of my local server. 
now i need to upload this site to my domain. but i can not change the connection string because in web.config file there is no connection strings....i manually write connection string there. but that does not work. i am in great problem. please help me to sort out this problem and meet my clients deadline...