mouse in openGL, double click ??

[a04 lqd]

here is the code:

int _xC,_yC;
void OnMouse(int button, int state, int x, int y)
{
int xMax = glutGet(GLUT_WINDOW_WIDTH);
int yMax = glutGet(GLUT_WINDOW_HEIGHT);
_xC = x;
_yC = yMax-y;

}

with this code , left click get xC and yC. use this, i want to make Point array to save x-axis and y-axis of point which is defined by left click by Onmouse code. but how to stop??? can i use right click or double click to break ???