Kernel 32 function

My application is failing when I use the following external functions to get/set the control setting from a communication device

 

FUNCTION boolean GetCommState(ulong hFile,REF dcb lpDCB) LIBRARY "KERNEL32.DLL"

 

FUNCTION boolean SetCommState(ulong hFile, REF dcb lpDCB) LIBRARY "KERNEL32.DLL"

 

What could be the reason?

Did the above dll functions are obsolete now? If yes what are the equivalent new functions? From where we can get the required information?

 

Any help is greatly appreciated