C++ :: Can't Refresh Checkers Board On Application

I Cant get my checkers game board to refresh every time i make a move. i have system("cls") But it does nothing of the sort.. To move a pice ive created an illusion which swaps one pieces appearance with another :

void getpiecetomove(int startx,int starty, int endx, int endy) {
boardpiece tmp;
//Regular Moves Pieces
tmp = board[startx][starty];
board[startx][starty] = board[startx+1][starty+1];
board[startx+1][starty+1] = tmp;
system("cls");
}