-7-(-3)
A scroll button or mouse wheel.
Press both mouse buttons at the same time.
Middle Mouse Button Cheers
The middle mouse button is usually the scroll wheel. Push the wheel down to click it.
Place the mouse pointer over the [x] sign in the tab and click. Or if you are in the tab you want to close, press Ctrl+W Or Use your middle mouse button Mouse over the tab you want to close and press the middle mouse button.
external part are left , middle ,and right mouse button, palm rest.and long wire.
It means a button which is neither the left nor right button on a mouse. Many have a middle button, sometimes in the form of a wheel, that can be pressed down to act as a button. This would be considered Button 3 on a mouse, but some could also have a button positioned where the user's thumb is.
To bind the impulse 101 command to a mouse button in Half-Life, you first need to open the console using the "~" key, then type in "bind mouse3 impulse 101" to bind the command to the middle mouse button (mouse3). You can replace "mouse3" with a different button number to bind it to a different mouse button.
http://69.10.233.10/KB/cpp/MBtn2DblClickVC.aspx
secondary mouse button
The mouse button that is the most used is the 'left side' of the mouse.
you have to press the middle scroll button/wheel on the mouse