battleship-like C Program

(500 pts)
The first part explains the program and what it should do(this is just the first part). The second part is my sourcecode.It compiles correctly,btw.I know it has something to do with my damn loops! Please help! also, i added fflush(stdin) and I think it's working correctly, please verify.
Instructions:
Part 1.1: Write a function with the following prototype:

void clearBoard (int rows, int columns, int * boardPtr);

The function should write a zero value to each element in the passed 2-D array.

Part 1.2: Write a function with the following prototype:

void showBoard (int rows, int columns, int * boardPtr);

The function should display the array. If the value of a board location is 0 to 9, print that value, otherwise print "x". Example:

int board [3][3] = { {0, 0, 1}, {99, -2, 7}, {-1, 6, 0} };
/* ... */
showBoard(3, 3, board);
/* ... */

Should display:

0 0 1
x x 7
x 6 0

Part 1.3: Write a function that reads board coordinates, with the following prototype:

int getCoords (int maxRow, int maxCol, int * row, int * col);

The function should read a character followed by a number, and convert these into a row, column pair that is output through the row, col parameters. The function should return 0 if an invalid entry was made, or a 1 if a valid entry was made. Example:

...
printf("Enter coordinates : ");
while (0 == getCoords(3, 3, &myRow, &myCol))
{
   printf("Bad coordinates!\nEnter coordinates : ");
}
printf("myRow = %d, myCol = %d\n", myRow, myCol);
...

Example output:

Enter coordinates: yy zz
Bad coordinates!
Enter coordinates : 0 0
Bad coordinates!
Enter coordinates : A10
Bad coordinates!
Enter coordinates : A 9
Bad coordinates!
Enter coordinates : B 2
myRow = 1, myCol = 1

The following chart might help illustrate how this coordinate system works:

    1     2     3     4     ...
A (0,0) (0,1) (0,2) (0,3) ...
B (1,0) (1,1) (1,2) (1,3) ...
C (2,0) (2,1) (2,2) (2,3) ...
D (3,0) (3,1) (3,2) (3,3) ...
...

Where the output row and column numbers are given as (row, column).

Part 1.4: Write a function with the following prototype:

void paintSpace (int rows, int cols, int * boardPtr);

The function should read a "Battleship" coordinate using the getCoords() and an integer value from the console. The integer value should be written to the board array corresponding to the input coordinate.

Part 1.5: Write a menu loop (in main(), for now) that asks the following:

************************************************************
0 - Clear the board.
1 - Paint a space.
2 - Show board.
3 - Play game.
4 - Quit
************************************************************
Your choice? _

If they select 0, zero all the values of the board. If they select 1, ask for coordinates and an integer value to write to the board. Then write that value to the board. If they select 2, display the board using the showBoard() function. If they select 3, tell the user that the game isn't ready yet. If they select 4, exit the program. Otherwise, tell the user their input was invalid. Use a 10x10 board

My SourceCode:
#include<stdio.h>
#include<stdlib.h>

void clearBoard(int rows, int columns, int * boardPtr);
void showBoard(int rows, int columns, int * boardPtr);
int getCoords(int maxRow, int maxCol, int *row, int *col);
void paintSpace(int rows, int cols, int * boardPtr);

void clearBoard(int rows, int columns, int * boardPtr)
{
int i;

for(i=0; i < rows * columns; i++)
   {
      *(boardPtr+i) = 0; //initialize value to 0
   }
} // End of clearBoard function.


void showBoard(int rows, int columns, int * boardPtr)
{
int i;
for(i=0; i < rows * columns; i++)
   {
   // Print newline character is row is finished.
   // If i modulus the columns is 0, then you've reached
   // the end of a row and need to print a newline.
   if(i % columns == 0)
      {
      printf("\n");
      }
   
   if ((*(boardPtr+i) >= 0) && (*(boardPtr+i) <= 9))
      {
      printf("%d ", *(boardPtr+i));
      }
   else
      {
      printf("x ");
      }
   }
}

int getCoords(int maxRow, int maxCol, int *row, int *col)
{
char myRowchar;
int myCol=0;
int myRownum=0;

scanf("%c %d", &myRowchar, &myCol);
myRownum = (int)myRowchar;

if(myRownum >= 97)
   {
   myRownum = myRownum - 97;
   }
else if((myRownum >=65) && (myRownum <=90))
   {
   myRownum = myRownum - 65;
   }  

if (myRownum > maxRow)
   {
   *row = 0;
   *col = 0;
   return 0;
   }
else if (myCol > maxCol)
   {
   *row = 0;
   *col = 0;
   return 0;
   }
else
   {
   *row = myRownum;
   *col = myCol - 1; // Need to compensate because array starts at 0.
   }
return 1;
}

void paintSpace(int rows, int cols, int * boardPtr)
{
int myRow = 0, myCol = 0, value = 0;

printf("Enter coordinates :");

while( 0 == getCoords(rows, cols, &myRow, &myCol))
{
   printf("Bad coordinates!\nEnter coordinates: ");
}
/*printf("myRow = %d, myCol = %d\n", myRow, myCol);*/

printf("Enter a value: ");
scanf("%d", &value);
value = *(boardPtr + (myRow*cols) + myCol) ;

}

int main()
{
int choice;
int rows = 10;
int columns = 10;
int boardPtr[rows][columns];

while(1)
{
   printf("\n*************************************************\n");
   printf("0 - Clear the board.\n");
   printf("1 - Paint a space.\n");
   printf("2 - Show board.\n");
   printf("3 - Play game.\n");
   printf("4 - Quit.\n");
   printf("*************************************************\n");
   printf("Your choice? _");
   scanf("%d", &choice);

   switch(choice)
      {
      case 0:
         clearBoard(rows, columns, (int *)boardPtr);
         break;

      case 1:
       fflush(stdin);
 paintSpace(rows, columns, (int *)boardPtr);
         break;

      case 2:
         showBoard(rows, columns, (int *)boardPtr);
         break;

      case 3:
         printf("The game isn't ready yet.\n");
         break;

      case 4:
         exit(0);

      default:
         printf("Your input was invalid.\n");
         break;
      } //End of Switch statement
   } //End of while loop
 return 0;
} //End of Program