Command line args & seg faults

EDIT: thanks ataxi for pointing out my now obvious goof up!

Hey all. This is my first post here. Be gentle ;)

I'm working on a project for school, and unfortunately I'm having problems understanding why I'm getting seg faults with my command line arguments.
Here are the important bits of my code: (The fn's Get2DSpace and Free2DSpace were written by my teacher & I know they work fine... and am assuming I'm using them correctly. Inputs: # of rows & cols to be in the array. Output: The pointer to the memory)

#include 

/* ---------------------MAIN------------------- */
int main( int argc, char *argv[] )
{
   FILE *ofp;
   int **gameboard, **moves;
   int rows = 0, cols = 0;
   
   rows = atoi(argv[1]);
   cols = atoi(argv[2]);

   /*error check for args and file opening*/
   if (argc != 4)
   {
      fprintf (stderr, "This program requires command line arguments\n");
      fprintf (stderr, "Please enter the number of rows, number of  \n");
      fprintf (stderr, "columns, and the name of the output file. \n\n");
      exit (-1);
   }
  
   ofp = fopen (argv[3], "w");
   if (ofp == NULL)
   {
      fprintf(stderr, "Sorry, couldn't open output file:\n");
      fprintf(stderr, "%s\n", argv[2]);
      exit (-2);
   }

   /*allocate space for the two arrays */
   /* I left this part in because the whole memory allocation thing is where I've historically overlooked things & 
   /* gotten seg faults */

    gameboard = GetTwoDSpace(rows, cols);
    moves = GetTwoDSpace(rows, cols);

   /* edited out a bunch of stuff that is mostly printf statements and stuff that shouldn't cause seg faults */
  
   /* close files and free up memory */
   fclose(ofp);
   FreeTwoDSpace(gameboard, rows);
   FreeTwoDSpace(moves, rows);

 return(0);
}

/*  ------------------------------------------  */ 

When I enter in 3 or 4 command line args, my program runs just fine. When I enter in only 1 or 2, I seg fault. Can anyone point out where I'm messing up?

Just to illustrate, here's typical output (from unedited code & debugging printf statements):

% a.out
Segmentation Fault
% a.out 3 
Segmentation Fault
% a.out 3 5
rows = 3 cols = 5
This program requires command line arguments
Please enter the number of rows, number of
columns, and the name of the output file.
% a.out 3 5 more
rows = 3 cols = 5
argv[0] = a.out
argv[1] = 3
argv[2] = 5
argv[3] = more
(reading the file more prints this same information)
%

Any input you have is greatly appreciated!