Need help On this c++ program.

for C++, Create a function called binary that will take a decimal number (can assume short int) and return a string of binary digits. Since it is short int, the largest string of digits would be about 16 assume the number is positive.

Have the main program input the numbers, check to make sure the number is not not negative. If they are print an error message. Otherwise call the binary function and print the answer.