I have a few nested loops, and I need the innermost one to wait until a button has been pressed. Don't know why the solution is escaping me, but can somebody please help me out here?

    for (roundNo = 1; roundNo <=3; roundNo ++) //start of the round
    {   
        if(!isBoardSet)
        {   Debug.Log("RoundNo = "+roundNo);
            var board_new = GameObject.Find("board_new");
            var randDist: float; //distance for the new board
            randDist = Random.Range(9.0, 12.0)/3.2808398950131234 ; //this is 9 - 12 feet converted to meters
            board_new.transform.position =Vector3(randDist, .156, 0);
            for (var playerNo: int = 1; playerNo <= noPlayers; playerNo ++) //start of the player's turn
            { Debug.Log("playerNo = "+playerNo);
                for (var tossNo: int = 1; tossNo <= 3; tossNo ++)
                {    Debug.Log("tossNo = "+tossNo);
                    if (tossed) Debug.Log("tossNo = "+ tossNo);
                    //put in x and y vel
                    //var textFieldString = "Enter x vel";
                }//we need it to wait here and poll the Toss It button
            }
            isBoardSet = true;              
        } 
        xVel = GUI.TextField (Rect (140, 40, 120, 20), xVel);
        yVel = GUI.TextField (Rect (140, 70, 120, 20), yVel);
        //Debug.Log ("xVel = "+xVel+ "  yVel = "+yVel);
        GUI.Box (Rect (10,180,100,150), "Progress");
        GUI.Label(Rect(10, 210, 80, 20), "Round: "+ roundNo);
        GUI.Label(Rect(10, 240, 80, 20), "Player: "+ playerNo);
        GUI.Label(Rect(10, 270, 80, 20), "Toss: "+ tossNo);
        if (GUI.Button (Rect (140,100,80,20), "Toss It")) 
        {
            //call some function in trajectory2 
            tossed = true;
        }
    } //end of the round

Not sure, but do I need a coroutine and a yield?