TControl.OnClick
From OpenEUO
EV OnClick Occurs when the user clicks the control.
Use the OnClick event handler to respond when the user clicks the control. Usually OnClick occurs when the user presses and releases the left mouse button with the mouse pointer over the control. This event can also occur when the user presses the accelerator key for a button or check box or when he presses the spacebar while they have focus. The same goes for check boxes and radio buttons when their Checked property is changed.
