MouseButton

From OxeyeWiki

mouseButton(x, y, button, clickCount)
This hook is called when-ever the user clicks on a mouse button or scrolls the mouse wheel.
Parameter	Type	Description
x	An integer	The on-screen x coordinate of the mouse click.
y	An integer	The on-screen y coordinate of the mouse click.
button	An integer	Which button that was pressed. Button 0 is LEFT, 1 is RIGHT, 2 is MIDDLE, 3 is WHEEL UP and 4 is WHEEL DOWN
clickCount	An integer	This value is usually 1, but if the user clicks the same button rapidly at the same location (within 10 pixels of the previous click), then this value will increase for each click. You can use this to detect double-clicking.

Example

  local function onMouseButton(x, y, button, clickCount)

    print(x .. ", " .. y .. ", " .. button .. ", " .. clickCount)

    if button == 0 then
    elseif button == 1 then
    elseif button == 2 then
    end

  end

  hook.add("mouseButton", onMouseButton)