Guys i have created a imageButton in my layout file and set a circular png image as its background.but when i am running my application, its displaying me a square button with my given image placed in the middle of it.

```
<ImageButton
    android:id="@+id/imageButton1"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:layout_alignParentTop="true"
    android:layout_centerHorizontal="true"
    android:src="@drawable/sliderr" />

```