Here is my file. I want to change the background color of my image button when it is clicked so the user can see it is clicked because when I clicked it does not seem I clicked it but it is working. I can see on other questions that you need a drawable to be able to do it but i do not know what will I put in the xml file in the drawable folder. Can you please help me? Thank you.
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:orientation="vertical"
android:layout_width="fill_parent"
android:layout_height="fill_parent">
<RelativeLayout
    android:id="@+id/webViewHeaderArea"
    android:layout_width="fill_parent"
    android:layout_height="wrap_content" 
    android:background="@android:color/white">
    <ImageButton
        android:id="@+id/btnCloseWebView"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentRight="true"
        android:layout_centerHorizontal="false"
        android:layout_centerInParent="true"
        android:layout_marginTop="10dp"
        android:layout_marginRight="10dp"
        android:src="@drawable/close"
        android:background="@null"
        android:contentDescription="@string/button" />
    <ImageButton
        android:id="@+id/btnReload"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_toLeftOf="@+id/btnCloseWebView"
        android:src="@drawable/reload"
        android:background="@null"
        android:contentDescription="@string/button" />
    <ImageButton
        android:id="@+id/btnBack"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_alignParentLeft="true"
        android:layout_centerVertical="true"
        android:layout_marginLeft="15dp"
        android:src="@drawable/back"
        android:background="@null"
        android:contentDescription="@string/button" />
    <ImageButton
        android:id="@+id/btnStop"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_marginLeft="17dp"
        android:layout_toRightOf="@+id/btnBack"
        android:src="@drawable/stop"
        android:background="@null"
        android:contentDescription="@string/button" />
    <ImageButton
        android:id="@+id/btnForward"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_marginLeft="16dp"
        android:layout_toRightOf="@+id/btnStop"
        android:src="@drawable/forward"
        android:background="@null"
        android:contentDescription="@string/button" />
</RelativeLayout>
    <WebView android:id="@+id/web_engine"
        android:layout_height="fill_parent"
        android:layout_width="fill_parent" />
 
     
     
    