Record last mouse click for use in a statment

[beep]

I am trying to find out how to record last mouse event so that i can use it in a statement for example.

private void blueballoon_click(object sender, MouseButtonEventArgs e)
        {
            if (last_click == "green" "brown" "red")
            {
                PopBalloonCount--;
            }
            else
            {
                PopBalloonCount++;
            }
            score.Content = "Your Score" + " " + Convert.ToString(PopBalloonCount);
        }   

        private void greenballoon_click(object sender, MouseButtonEventArgs e)
        {
            if (last_click == "blue") 
             { 
                 PopBalloonCount++;
             }
            else 
             { 
                 PopBalloonCount--;
             }
            score.Content = "Your Score" + " " + Convert.ToString(PopBalloonCount);
        }

Is there a simple way of doing this and if so how?