Re-link lots of images? Indesign CS3

var myDoc = app.activeDocument;

var myImages = myDoc.allGraphics;

var myPages = myDoc.pages;

// If the document doesn't contain any images, give alert and exit

if (myImages.length == 0) {

   alert("This document doesn't contain any images.", "Script will be terminated");

   exit();  

}



for (var p = 0; p < myPages.length; p++) {

   var myPageNumber = pagenum(myPages
.name);

   for (i = myImages.length-1; i >= 0 ; i--) {

      var myLink = myImages.itemLink;

      var myImageCounter = i + 1;

      var myImageNumber = pagenum(myImageCounter);

      var myOldLinkName = myLink.name;

      // I assume that all extensions consist of 3 characters

      var myExtension = myOldLinkName.substr(-4, 4);

      var myNewLinkName = "PAGE_" + myPageNumber  + "_image" + myImageNumber + myExtension;

      var myOldImageFile = new File (myLink.filePath);

      var myOldPath = myOldImageFile.toString();

      var myNewPath = myOldPath.replace(myOldLinkName, myNewLinkName);

      myOldImageFile.rename(myNewPath);

      myLink.relink (myOldImageFile); 

      myLink.update();

   }

}



function pagenum(myNumber){

   if (myNumber >= 1 && myNumber <= 9)

   {

   x =  "0" + "0" + myNumber;

   }

   else if (myNumber >= 10 && myNumber <= 99)

   {

   x = "0" + myNumber;

   }

   else if (myNumber >= 100 && myNumber <= 999)

   {

   x = myNumber;

   }

return x

}