hi frnds i am trying to put the LED simulation in the keil( i got the same from www.c51.de/.../uVision2DLLs.php) ,but that is not working out.i did all the steps which is mentioned in the page from which i downloaded DLL.but it is giving some error,even the version they mentioned is also the same .i tried running the program Traffic which is already given. please help thanx in advance Arun