I've looked everywhere for this function and cannot find the header files to make this work. It says clrscr() undeclared which brings me to the question. Is clrscr(); a function in C++?
It used to be a function in <conio.h>, in old Borland C compilers.
It's not a C++ standard function.
And before someone posts the usual "please email me the conio.h file" request, can I point out that this ancient Borland header file only contained the declaration of the function. You would also need the supporting Borland library, which will not be compatible with any modern C++ compilation system.