onmousedown Property
Returns or sets a Variant that represents the value of the onmousedown attribute that is the name of the script to run when the onmousedown event fires.
expression.onmousedown
expression Required. An expression that returns one of the objects in the Applies To list.
Example
The following example sets the onmousedown attribute for the BODY element in the active document.
ActiveDocument.body.onmousedown = "script()"