I am debuggin my application in PB 11.5. I have used windows api GetUserNameA. But during debugging, when it comes to this API, applcation fails.. It s unable to find refrence to this API. How do i get Powerbuilder to identify this API? The declaration is fine. Is there any other thing that I have missed ? I have declared this functions as Global External Function and I am calling this function from Application Open event. Am I missing anything? Pls help.