BackgroundImage problem with my back button - iphone

Question

I have a concern that the image I attributed back button does not appear I added this statement but it does nothing
win1.setBackButtonTitleImage('back.png');
here is the code
var ButtonRetour = Ti.UI.createButtonBar({labels:['Retour'],
backgroundColor:'#ae4041',
backgroundImage:'back.png',
color:'#ffffff' });
ButtonRetour.addEventListener('click',
function(){ tabGroup.close(); });
win1.leftNavButton = ButtonRetour;
win1.setBackButtonTitleImage('back.png');
you have an idea about the problem
thank you
I found the solution
I actually changed the code for the creation of back button using the following
var backButton = Ti.UI.createButton({
title:'Accueil',
backgroundImage:'images/back.png',
font:{fontSize:13,fontWeight:'bold'},
textAlign:'center',
width:75,
height: 35
});
backButton.addEventListener('click', function(){
tabGroup.close();
});
win1.leftNavButton = backButton;

Answer 1

Try that. Note, that I am not sure whether you can use both backgroundColor and backgroundImage:
var ButtonRetour = Titanium.UI.createButton({
title:'Retour',
backgroundColor: '#ae4041', // i am not sure whether you can use both bgColor and bgImage
backgroundImage:'back.png',
width:100, //set proper width here
height:20 //set proper height here
});
ButtonRetour.addEventListener('click', function() {
tabGroup.close();
});
win1.leftNavButton = ButtonRetour;