How to put multiple values into an array?

[Simonetos The Greek]

With this part of code, I am trying to put all found layer names (layersData) into dropdownlist2_array, but instead of a list with names, I get one line with all names!!! Any idea what am I doing wrong? Thank you in advance!!!

var layerNames = [];
for (var i = 0; i < layersData.length; i++)
{
    var layerName;
    layerName = layersData.name;
    layerNames.push(layerName);
};
var dropdownlist2_array = [layerNames]; 
var dropdownlist2 = panel2.add("dropdownlist", undefined, dropdownlist2_array); 
dropdownlist2.selection = -1; 
dropdownlist2.text = "Layer Name:"; 

[SuperMerlin · Accepted solution]

var w = new Window("dialog","test",undefined,{closeButton: true});
var layerNames = [];  
var layersData=activeDocument.layers;
for (var i = 0; i < layersData.length; i++)  {  
    layerNames.push(layersData.name);  
}     
var dropdownlist2 = w.add("dropdownlist", undefined, layerNames);   
dropdownlist2.selection = 0;   
dropdownlist2.text = "Layer Name:"; 
w.show();

[Simonetos The Greek]

One more question... What should I do If I want to avoid duplicates? Thank you for your time!!!

[SuperMerlin]

var w = new Window("dialog","test",undefined,{closeButton: true});
var layerNames = [];  
var layersData=activeDocument.layers;
for (var i = 0; i < layersData.length; i++)  {  
    layerNames.push(layersData.name);  
}    
layerNames = UniqueSortedList(layerNames);
var dropdownlist2 = w.add("dropdownlist", undefined, layerNames);   
dropdownlist2.selection = 0;   
dropdownlist2.text = "Layer Name:"; 
w.show();
function UniqueSortedList(ArrayName){
var unduped = new Object;
for (var i = 0; i < ArrayName.length; i++) {   
unduped[ArrayName] = ArrayName;
}
var uniques = new Array;for (var k in unduped) {
   uniques.push(unduped);}
return uniques.sort();
}

[Simonetos The Greek]

Thank you so much!!!