JavaScript Editor opens when I click Run Sequence

Question

I'm using Batch Sequences to add Headers to my documents, using addWatermark from Text.  I want the file name as part of the watermark.
The reason I'm using javascript rather than the provided sequence is that I have a few hundred documents and they have a different amount of pages.
When I click run sequence the javascript editor pops up and if I click OK then everything runs fine, the new doc is created with the header I wanted. 
But I don't want to click OK a few hundred times and it wasn't happening before, it just started. Is there a way to stop it from popping up? Or a way to figure out why it started?
I'm on Acrobat 9 Pro 9.0.0 and Windows XP. 
The code is below:
/*Adding a header to a document*/
//This gets the filename
var re = /\.pdf$/i;
// filename is the base name of the file Acrobat is working on
var filename = this.documentFileName.replace(re,"");
//This adds a header in the right top position
this.addWatermarkFromText({
cText: "(My right header -" + filename +")",
nStart: 2, //Page to start adding the header
nEnd: this.numPages-1,  //Pages to stop adding the header
cFont:font.Helv,
nFontSize:10,
nTextAlign: app.constants.align.right,
nHorizAlign: app.constants.align.right,
nVertAlign: app.constants.align.top,
nHorizValue: -72,
nVertValue: -72

Answer 1

Make sure the "Prompt user" check-box under the Execute JavaScript command
in your Action is not ticked.