Photoshop: script for zooming in

Photoshop: zoom300.jsx

main();
function main(){

// Change the value between the parentheses below
// into your desired percentage:
setZoomLevel(300);

// Leave the code below unchanged
function setZoomLevel(zoom){
if(zoom < 1) zoom =1;
var ref = new ActionReference();
ref.putEnumerated(charIDToTypeID("capp"), charIDToTypeID("Ordn"), charIDToTypeID("Trgt"));
var getScreenResolution = executeActionGet(ref).getObjectValue(stringIDToTypeID('unitsPrefs')).getUnitDoubleValue(stringIDToTypeID('newDocPresetScreenResolution'))/72;
var docResolution = activeDocument.resolution;
activeDocument.resizeImage(undefined, undefined, getScreenResolution/(zoom/100), ResampleMethod.NONE);
var desc = new ActionDescriptor();
ref = null;
ref = new ActionReference();
ref.putEnumerated(charIDToTypeID("Mn  "), charIDToTypeID("MnIt"), charIDToTypeID('PrnS'));
desc.putReference(charIDToTypeID("null"), ref);
executeAction(charIDToTypeID("slct"), desc, DialogModes.NO);
activeDocument.resizeImage(undefined, undefined, docResolution, ResampleMethod.NONE);};};

Thank you so much. It's a big help for me.

Hello, is it possible to do the same thing but on a layer ? I need to zoom on a layer when the user click on a button.. Thank you in advance !