Replace images on specific layer

Question

Hi,
till now i used the Script-function in InDesign only for "findandchange"-Actions. It works fine and is very time-saving.
Now I would like to replace images on specific Layers, like I do this with textcontent with the "Findandchange"-Script.
Is this possible?
I try to explain...
Example:
- Find all images "image-a1.tif"(path:folder/folder/image-a1.tif) on specific layer "mylayer"(or only activ and not locked layers)
- Replace all this images with this image "image-a2"tif(path:folder/folder/image-a2.tif)
- Find all images "image-b1.tif"(path:folder/folder/image-b1.tif) on specific layer "mylayer"(or only activ and not locked layers)
- Replace all this images with this image "image-b2"tif(path:folder/folder/image-b2.tif)
- Find all images "image-c1.tif"(path:folder/folder/image-c1.tif) on specific layer "mylayer"(or only activ and not locked layers)
- Replace all this images with this image "image-c2"tif(path:folder/folder/image-c2.tif)
Background Info:
These images have all the same size and resolution. They distinguish only in content (english-/france/german elements).
It's a "multilanguage" InDesign-Document. Every "Languagecontent" have its own layer.
Thanks for helping...

Answer 1

Hi,
Yes you can. I.e using dialog box.
It could be like this:
myDoc = app.activeDocument;
myGraph = myDoc.layers.item("graphic").allGraphics;     // modify layer name
for (k=0; k<myGraph.length; k++)
     oldLink = myGraph[k].itemLink.filePath;     //whole path
     oldFileName = File(oldLink).name;              //only file name
    newFileName = myDialog(oldFileName);     // new name is read from dialog
     if ( !newFileName ) continue;                         // if user press "cancel" button - no action
     newLink = File(oldLink.replace(oldFileName,newFileName) );    // replace file names within path
     if (File(newLink) instanceof File)                     // if wrong newLink - no action
        myGraph[k].itemLink.relink(newLink);     //relink graphic
function myDialog(oldName)
    var myWindow = new Window ("dialog", "Replacing images");
    var myInputGroup = myWindow.add ("group");
    myInputGroup.orientation = "column";
    myInputGroup.alignChildren = "left";
    myInputGroup.add ("statictext", undefined, "Old Name: " + oldName);
    myInputGroup.add ("statictext", undefined, "New Name:");
    var myText = myInputGroup.add ("edittext", undefined, ".eps");
    myText.characters = 20;
    myText.active = true;
    var myButtonGroup = myWindow.add ("group");
    myButtonGroup.alignment = "right";
    myButtonGroup.add ("button", undefined, "OK");
    myButtonGroup.add ("button", undefined, "Cancel");
    var OKbutton = myWindow.show ();
        if (OKbutton == 1) myRes = myText.text;
        else myRes = false;
    return myRes;