why am i getting this error while running the javascript for adding watermark from file??

Hi,

I am using adobe acrobat 9 professional .I need to add watermarkfrom file  to a pdf document by clicking  a button on the document which runs the following javascript

this.addWatermarkFromFile({
cDIPath: "/C/watermark.pdf",
nSourcePage: 1,
nEnd: 9,
nHorizAlign: 0,
nVertAlign: 0,
nHorizValue: 144,
nVertValue: -72,
nRotation: 45
})

Java debugger prompts the following message while running it

NotAllowedError: Security settings prevent access to this property or method.
Doc.addWatermarkFromFile:9:AcroForm:watermark:Annot1:MouseUp:Action1

Can anyone please help me out how to get acces to the method addWatermarkFromFile ?