C :: Error Using File Descriptor

Why I am getting an error (-1) when trying to write to a file. Here is the function - I did not include the rest of the code - not sure if I am leaving anything else out - I assumed it was a write permission issue?

Code:
#defineDATAFILE "/var/chance.data" //File to store userdata
voidregister_new_player() { int fd;
printf("-=-={New Player Registration } =-=-
");
printf("Enteryour name: ");
input_name();

[Code] .....

Result

Code:
user@ubuntu:~/examples$./game_of_chance
-=-={New Player Registration } =-=-
Enteryour name: test
[!!]Fatal Error in register_new_player() while opening file:Success
user@ubuntu:~/examples$