Thread: Problem with isalpha

I have a doubt about the isalpha function
The literature says that it accepts a variable of type char.
But I sent a pointer to a char
This is what I did

Code:

if(isalpha(*(argv+(temp_counter))!=0)
{
      printf("The string starts with a letter\n");
      printf("The first letter is %c\n",*(argv+(temp_counter));
}

It seems to compile and run fine on my comp. I am ussing gcc to compile it. But when I sent it to a friend it did not compile on his comp.
Any idea why this might be happening.
Thanks in advance.