I have a stored procedure that has an if statement in it. If the number of rows counted is greater than 0 then it should set the only output parameter @UserId to 0<
@UserId
Try to call your proc in this way:
DECLARE @UserIDout int EXEC YOURPROC @EmailAddress = 'sdfds', @NickName = 'sdfdsfs', ..., @UserId = @UserIDout OUTPUT SELECT @UserIDout