WCF Issue

Hi all i have created a WCF web application. At one point the application started behaving unexpectedly. Like what ever modifications i have added to it, is not reflecting in the cosuming time. I have chaged the code but its not getting recomplied. It seems to be running the older version from somewhere else. I have created another workspace and copied the files to it. Again no use. Its running from some where else. The new work space is not building when i run the application. Can any one help me in this.