How to Put the Back Button in Left of my ActionBar

I'm building and finishing a Android App and this is one of the main things I need to Fix it up.

So, I have a Action Bar styled like this:

Blockquote

<resources>
    <style name="MyCustomTheme" parent="@android:style/Theme.Holo.Light">
        <item name="android:actionBarStyle">@style/MyActionBarTheme</item>
    </style>

    <style name="MyActionBarTheme" parent="@android:style/Widget.Holo.Light.ActionBar">
        <item name="android:background">#F6E6E7</item>
        <item name="android:textSize">10sp</item>
    </style>

    <style name="CustomTabWidget">
        <item name="android:textSize">15sp</item>
    </style>


</resources>

Blockquote

And this is the layout where i put the button

<menu xmlns:android="http://ift.tt/nIICcg" >
    <!-- Search, should appear as action button -->

    <item android:id="@+id/voltar"
        android:title="Voltar"
        android:icon="@drawable/abc_ic_ab_back_holo_light"
        android:showAsAction="ifRoom" />
    <!-- Settings, should always be in the overflow -->

</menu>

Blockquote

this Button Tittled Voltar is at the Right Side of the Action Bar.. What Should I Do to put this on Left Side?

Thank you for read this