Keeping score without the actual score in C#

I'm trying to keep score and other than the very first question, nothing else registers. The if-statement seems to work other than the whole not keeping score

if (correctAns == ans1 && ans1RadioBtn.Checked == true)
            {
                correctAnsLabel.Text = "Correct!";
                score = +1;
                scoreLabel.Text = "Total Score: 100   Your Score: " + score;
            }
            else if (correctAns == ans2 && ans2RadioBtn.Checked == true)
            {
                correctAnsLabel.Text = "Correct!";
                score = +1;
                scoreLabel.Text = "Total Score: 100   Your Score: " + score;
            }
            else if (correctAns == ans3 && ans3RadioBtn.Checked == true)
            {
                correctAnsLabel.Text = "Correct!";
                score = +1;
                scoreLabel.Text = "Total Score: 100   Your Score: " + score;
            }
            else if (correctAns == ans4 && ans4RadioBtn.Checked == true)
            {
                correctAnsLabel.Text = "Correct!";
                score = +1;
                scoreLabel.Text = "Total Score: 100   Your Score: " + score;
            }
            else
            {
                correctAnsLabel.Text = "Incorrect. The answer is " + correctAns + "!";
                score = -1;
                scoreLabel.Text = "Total Score: 100   Your Score: " + score;

            }

I have no idea why it won't keep the damn score!