help w/ using a var in a changing a property

Question

Hey all, Have a problem that is twisting my mind into a pretzel. I am wanting to use a int variable in a line of code inside a function. I am passing into the function which button to alter background image in the "box" variable. I really do not want to type out 20 lines of code for each button. Here is the code snippet. private void track(string turn, int box) { if (turn = "x") { this.btnPos[box].BackgroundImage = global::TicTacToe.Properties.Resources.x; // Set boxes array position 1 to x boxes[1] = "x"; // Change whos turn it is. whosturn = "o"; this.plTurn.BackgroundImage = global::TicTacToe.Properties.Resources.o; } else { this.btnPos[box].BackgroundImage = global::TicTacToe.Properties.Resources.o; // Set boxes array position 1 to x boxes[1] = "o"; // Change whos turn it is. whosturn = "x"; this.plTurn.BackgroundImage = global::TicTacToe.Properties.Resources.x; When I debug the app, I keep getting "tictactoe.form1 does not contain a definition for btnPos" There are definitions for btnPos1, btnPos2,.....btnPos9. Main reason for wanting to have a function is that the teacher only gives an A if you compress the code functionality down as much as possible. Any help or pointers would be appreciated.