Alright I am writing tic tac toe for school project I was wondering if I am gonna get anywhere this I can't figure out a way to keep the old tic tac toe board and add X's and O's look at this please

#include <iostream.h>
#include <stdlib.h>
#include <string.h>

int gridchange();
int begin(int fplayer);
int selgrid(int gridnum);

char one, two, three, four, five, six, seven, eight, nine;
int fplayer, gridnum;
char grid1[] = " || || \n || || \n_____||_____||_____\n";
char grid2[] = "_____||_____||_____\n || || \n || || \n_____||_____||_____\n";
char grid3[] = "_____||_____||_____\n || || \n || || \n || || \n";

int gridchange()
{
if (fplayer == 1)
{
if (gridnum == 1)
{
strcpy(grid1," || || \n x || || \n_____||_____||_____\n");
}

else if (gridnum == 2)
{
strcpy(grid1," || || \n || x || \n_____||_____||_____\n");
}

else if (gridnum == 3)
{
strcpy(grid1," || || \n || || x \n_____||_____||_____\n");
}

else if (gridnum == 4)
{
strcpy(grid2,"_____||_____||_____\n || || \n x || || \n_____||_____||_____\n");
}

else if (gridnum == 5)
{
strcpy(grid2,"_____||_____||_____\n || || \n || x || \n_____||_____||_____\n");
}

else if (gridnum == 6)
{
strcpy(grid2,"_____||_____||_____\n || || \n || || x \n_____||_____||_____\n");
}
else if (gridnum == 7)
{
strcpy(grid3,"_____||_____||_____\n || || \n x || || \n || || \n");
}

else if (gridnum == 8)
{
strcpy(grid3,"_____||_____||_____\n || || \n || x || \n || || \n");
}

else if (gridnum == 9)
{
strcpy(grid3,"_____||_____||_____\n || || \n || || x \n || || \n");
}
}
else if (fplayer == 2)
{
if (gridnum == 1)
{
strcpy(grid1," || || \n o || || \n_____||_____||_____\n");
}

else if (gridnum == 2)
{
strcpy(grid1," || || \n || o || \n_____||_____||_____\n");
}

else if (gridnum == 3)
{
strcpy(grid1," || || \n || || o \n_____||_____||_____\n");
}

else if (gridnum == 4)
{
strcpy(grid2,"_____||_____||_____\n || || \n o || || \n_____||_____||_____\n");
}

else if (gridnum == 5)
{
strcpy(grid2,"_____||_____||_____\n || || \n || o || \n_____||_____||_____\n");
}

else if (gridnum == 6)
{
strcpy(grid2,"_____||_____||_____\n || || \n || || o \n_____||_____||_____\n");
}
else if (gridnum == 7)
{
strcpy(grid3,"_____||_____||_____\n || || \n o || || \n || || \n");
}

else if (gridnum == 8)
{
strcpy(grid3,"_____||_____||_____\n || || \n || o || \n || || \n");
}

else if (gridnum == 9)
{
strcpy(grid3,"_____||_____||_____\n || || \n || || o \n || || \n");
}

}
return 0;
}

int main()
{
do
{
cout << "Enter 1 for X first or 2 for O first: ";
cin >> fplayer;
}
while (fplayer > 1 && fplayer < 2);

do
{
cout << " 1 | 2 | 3 \n | | \n_____|_____|_____\n 4 | 5 | 6 \n | | \n_____|_____|_____\n 7 | 8 | 9 \n | | \n | | \n";
cout << "Please enter the grid number you would like to place your character in: ";
cin >> gridnum;
}
while (gridnum < 0 && gridnum > 9);
gridchange();
cout << grid1 << grid2 << grid3;

return 0;

}


any help would be appreciated.

Ryan