OnClick problems

Question

I'm having problems with this simple script that exports layer as images named after the layer name. The problem is the UI; I can't get the buttons to work properly. Either the cancel and ok buttons don't work or they both process the images. All or nothing.  Can someone please point out where I'm going wrong. Thank you.
app.preferences.rulerUnits = Units.PIXELS;
if (documents.length == 0) {
alert ("no documents open, dude!")
} else {
// call the source document
var srcDoc = app.activeDocument;
fileName = app.activeDocument.name;
// change this back to include the name of the source file as the base file prefix
// docName = fileName.substring(0,fileName.length -4)
var docName =""
var fileNum ="_";
var imageCount = 1
var numOfLayers = srcDoc.layers.length;
var layerRef = srcDoc.activeLayer;
var dlg=
"dialog{text:'Script Interface',bounds:[100,100,460,270],"+
"statictext0:StaticText{bounds:[60,10,300,80] , text:'Saves out each layer as a file named after the corresponding layer name. (Optional) Set the prefix of the files to be saved. Leave blank to omit this prefix. (default)' ,properties:{scrolling:undefined,multiline:true}},"+
"EditText:EditText{bounds:[60,90,300,106] , text:'myfile' ,properties:{multiline:false,noecho:false,readonly:false}},"+
"decant:Button{bounds:[60,120,160,140] , text:'OK' },"+
"exit:Button{bounds:[200,120,300,140] , text:'Cancel' },"+
var win = new Window(dlg,'Decant images by layer name');
win.center();
win.EditText.text = docName;
win.show();
var myDocName = win.EditText.text;
win.exit.onClick = function(){
win.close(1);
win.decant.onClick = function(){
processLayers (srcDoc);
function processLayers (srcDoc) {
for (var i = numOfLayers -1; i >= 0  ; i--)
if (imageCount < 10)
  fileNum = "_0";
  else fileNum ="_";
srcDoc.activeLayer = srcDoc.artLayers[i];
// find the selected layer name and call it mySelectedlayer
//var thisLayer = app.activeDocument.activeLayer.name;
var thisLayer = srcDoc.artLayers[i].name;
if (srcDoc.activeLayer.isBackgroundLayer == false) {
// duplicate image into new document
// =======================================================
var id2784 = charIDToTypeID( "Mk  " );
    var desc707 = new ActionDescriptor();
    var id2785 = charIDToTypeID( "null" );
        var ref508 = new ActionReference();
        var id2786 = charIDToTypeID( "Dcmn" );
        ref508.putClass( id2786 );
    desc707.putReference( id2785, ref508 );
    var id2787 = charIDToTypeID( "Nm  " );
      desc707.putString( id2787, myDocName + thisLayer );
    var id2788 = charIDToTypeID( "Usng" );
        var ref509 = new ActionReference();
        var id2789 = charIDToTypeID( "Lyr " );
        var id2790 = charIDToTypeID( "Ordn" );
        var id2791 = charIDToTypeID( "Trgt" );
        ref509.putEnumerated( id2789, id2790, id2791 );
    desc707.putReference( id2788, ref509 );
executeAction( id2784, desc707, DialogModes.NO );
// Set filePath and fileName to source path
filePath = srcDoc.path + '/' + app.activeDocument.name + '.png';
// save out the image
var pngFile = new File(filePath);
pngSaveOptions = new PNGSaveOptions();
pngSaveOptions.embedColorProfile = true;
pngSaveOptions.formatOptions = FormatOptions.STANDARDBASELINE;
pngSaveOptions.matte = MatteType.NONE; pngSaveOptions.quality = 1;
activeDocument.saveAs(pngFile, pngSaveOptions, false, Extension.LOWERCASE);
// close that save png
app.activeDocument.close()
// selects document that's been open the longest
app.activeDocument = srcDoc;
imageCount ++;
//var mySourceFilePath = activeDocument.fullName.path + "/";
alert ("Done! " + (numOfLayers -1) + " images" + "\n" + "were successfully exported to:" + "\n" + "\n" + filePath.substring(0,filePath.length -6));
} //no documents open

Answer 1

Are the onClick functions even necessary?
But I create dialogs the other way (Edit: which is less elegant):
var dlg = new Window("dialog", "space with distance", [500,300,750,380]);
// field for entry;
dlg.distance = dlg.add("edittext", [15,15,110,35], "50", {multiline:false});
dlg.distance.active = true;
// ok- and cancel-button;
dlg.buildBtn = dlg.add("button", [13,45,118,68], "OK", {name:"ok"});
dlg.cancelBtn = dlg.add("button", [128,45,240,68], "Cancel", {name:"cancel"});
// show dialog;
dlg.center();
// show dialog;
var myReturn = dlg.show ();
// if ok;
if (myReturn == true) {
    alert (dlg.distance.text)
else {
    alert ("canceled")