Need help in automating batch placing of images on spreads

As I mentioned earlier I have very little experience with JavaScript.

I also copied the ImageCatalog script to a new file and read it atleast five times, and tried to wrap my head around the flow of execution.

The comments were really helpful in the process.

I proritized what i want to achive with my script and started deleting unwanted code. I also tested it frequently.

Here is my script as it stands right now.

function Init(){

        var myFilteredFiles;

        //Make certain that user interaction (display of dialogs, etc.) is turned on.

        app.scriptPreferences.userInteractionLevel = UserInteractionLevels.interactWithAll;

        myExtensions = [".jpg", ".jpeg"]

        //Display the folder browser.

        var myFolder = Folder.selectDialog("Select the folder containing the images", "");

        //Get the path to the folder containing the files you want to place.

        if(myFolder != null){

                    if(File.fs == "Macintosh"){

                        myFilteredFiles = myMacOSFileFilter(myFolder);

                    }

                    else{

                        myFilteredFiles = myWinOSFileFilter(myFolder);

                    }

                    if(myFilteredFiles.length != 0){

                            myPlaceImages(myFilteredFiles);

                            alert("Done!");

                    }

              }

        }

// call the initial function

Init();

//Windows version of the file filter.

function myWinOSFileFilter(myFolder){

          var myFiles = new Array;

          var myFilteredFiles = new Array;

          for(myExtensionCounter = 0; myExtensionCounter < myExtensions.length; myExtensionCounter++){

                    myExtension = myExtensions[myExtensionCounter];

        myFiles = myFolder.getFiles("*"+ myExtension);

                    if(myFiles.length != 0){

                              for(var myFileCounter = 0; myFileCounter < myFiles.length; myFileCounter++){

                                        myFilteredFiles.push(myFiles[myFileCounter]);

                              }

                    }

          }

          return myFilteredFiles;

}

function myMacOSFileFilter(myFolder){

          var myFilteredFiles = myFolder.getFiles(myFileFilter);

          return myFilteredFiles;

}

//Mac OS version of file filter

//Have to provide a separate version because not all Mac OS users use file extensions

//and/or file extensions are sometimes hidden by the Finder.

function myFileFilter(myFile){

          var myFileType = myFile.type;

          switch (myFileType){

                    case "JPEG":

        return true;

                              break;

                    default:

                    for(var myCounter = 0; myCounter<myExtensions.length; myCounter++){

                              var myExtension = myExtensions[myCounter];

                              if(myFile.name.indexOf(myExtension)>-1){

                                        return true;

                                        break;

                              }

                    }

          }

          return false;

}

function myPlaceImages(myFiles){

        var myDocument = app.documents.item(0);

        var myDocumentPreferences = myDocument.documentPreferences;        

        var myNumberOfFiles = myFiles.length;

        alert(myNumberOfFiles);

        var myNumberOfPages = (myNumberOfFiles * 2) + 1;

        myDocumentPreferences.pagesPerDocument = myNumberOfPages;       

        var myPage = myDocument.pages.item(0);

        var myPages = myDocument.pages;

        for (myCounter = myDocument.pages.length-1; myCounter >= 0; myCounter--){ 

            if(myCounter%2 == 1){

                 myPage = myPages.item(myCounter);

                var myLiveWidth = myDocumentPreferences.pageWidth

                var myLiveHeight = myDocumentPreferences.pageHeight

                myY1 = 0

                myY2 = myLiveHeight

                myX1 = 0

                myX2 = myLiveWidth * 2

                myRectangle = myPage.rectangles.add(myDocument.layers.item(-1), undefined, undefined, {geometricBounds:[myY1, myX1, myY2, myX2], strokeWeight:0, strokeColor:myDocument.swatches.item("None")}); 

        }

    }

        for (myCounter = 0; myCounter < myNumberOfFiles; myCounter++){ 

            myFile = myFiles[myCounter]; 

            //alert(myFile);           

            myRectangle = myDocument.rectangles.item(myCounter);

            myRectangle.place(File(myFile));

        }

                    for (var myCounter = myDocument.rectangles.length-1; myCounter >= 0;myCounter--){ 

                              if (myDocument.rectangles.item(myCounter).contentType == ContentType.unassigned){

                                        myDocument.rectangles.item(myCounter).remove();

                              } 

                              else{

                                        //As soon as you encounter a rectangle with content, exit the loop.

                                        break;

                              }

                    }

}