UIHANDLER OnMouseDown

Invoked when a mouse button is pressed down on a widget.
 ScriptRegion OnMouseDown(self, button)
==Arguments==
:;self: - The widget receiving the mouse input
:;button: : 
==Example==
==Details==
Setting the OnMouseDown script automatically implies EnableMouse(true)
local f = CreateFrame("Frame")
print(f:IsMouseEnabled()) -- false
f:SetScript("OnMouseDown", function() end)
print(f:IsMouseEnabled()) -- true