Why cant i access xml files under drawable?
<p>First of all i am extremely new to android and i dont know much about it.I am trying to play around with it and i am right now following this tutorial:
<a href="http://www.androidhive.info/2011/08/android-tab-layout-tutorial/" rel="nofollow">http://www.androidhive.info/2011/08/android-tab-layout-tutorial/</a></p>

<p>I have created a class as below</p>

<pre><code>package com.example.tabbedactivity;

import android.app.TabActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.Menu;
import android.widget.TabHost;
import android.widget.TabHost.TabSpec;

public class TabbedActivity extends TabActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_tabbed);

        TabHost tabHost = getTabHost();

        // Tab for Photos
        TabSpec photospec = tabHost.newTabSpec("Photos");
        // setting Title and Icon for the Tab
        photospec.setIndicator("Photos", getResources().getDrawable(R.drawable.icon_photos_tab));
        Intent photosIntent = new Intent(this, PhotosActivity.class);
        photospec.setContent(photosIntent);

        // Tab for Songs
        TabSpec songspec = tabHost.newTabSpec("Songs");
        songspec.setIndicator("Songs", getResources().getDrawable(R.drawable.icon_songs_tab));
        Intent songsIntent = new Intent(this, SongsActivity.class);
        songspec.setContent(songsIntent);

        // Tab for Videos
        TabSpec videospec = tabHost.newTabSpec("Videos");
        videospec.setIndicator("Videos", getResources().getDrawable(R.drawable.icon_videos_tab));
        Intent videosIntent = new Intent(this, VideosActivity.class);
        videospec.setContent(videosIntent);

        // Adding all TabSpec to TabHost
        tabHost.addTab(photospec); // Adding photos tab
        tabHost.addTab(songspec); // Adding songs tab
        tabHost.addTab(videospec); // Adding videos ta
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.activity_tabbed, menu);
        return true;
    }

}
</code></pre>

<p>and accordingly i have made three xml files under drawable like shown below
icon_photos_tab.xml</p>

<pre><code>&lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
    &lt;!-- When selected, use grey --&gt;
    &lt;item android:drawable="@drawable/photo-hover"
          android:state_selected="true" /&gt;
    &lt;!-- When not selected, use white--&gt;
    &lt;item android:drawable="@drawable/photo-unhover" /&gt;
&lt;/selector&gt;
</code></pre>

<p>icon_songs_tab.xml</p>

<pre><code>&lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
    &lt;!-- When selected, use grey --&gt;
    &lt;item android:drawable="@drawable/music-hover"
          android:state_selected="true" /&gt;
    &lt;!-- When not selected, use white--&gt;
    &lt;item android:drawable="@drawable/music-unhover" /&gt;
&lt;/selector&gt;
</code></pre>

<p>icon_videos_tab.xml</p>

<pre><code>&lt;selector xmlns:android="http://schemas.android.com/apk/res/android"&gt;
    &lt;!-- When selected, use grey --&gt;
    &lt;item android:drawable="@drawable/video-hover"
          android:state_selected="true" /&gt;
    &lt;!-- When not selected, use white--&gt;
    &lt;item android:drawable="@drawable/video-unhover" /&gt;
&lt;/selector&gt;
</code></pre>

<p>now the IDE shows problem when i try to access these xml files under drawable precisely the line of codes shown below which are  part of TabbedActivity.java (the class that i have shown above)</p>

<pre><code>TabSpec songspec = tabHost.newTabSpec("Songs");
            songspec.setIndicator("Songs", getResources().getDrawable(R.drawable.icon_songs_tab));


TabSpec photospec = tabHost.newTabSpec("Photos");
            // setting Title and Icon for the Tab
            photospec.setIndicator("Photos", getResources().getDrawable(R.drawable.icon_photos_tab));


TabSpec videospec = tabHost.newTabSpec("Videos");
            videospec.setIndicator("Videos", getResources().getDrawable(R.drawable.icon_videos_tab));
</code></pre>

<p>and the error says </p>

<blockquote>
  <p>Multiple markers at this line
    - icon_photos_tab cannot be resolved or is       not a field
    - R.drawable cannot be resolved to a variable</p>
</blockquote>

<p>What exactly could be the problem.(I am really really new to android .This is kind of liek my first app and i havenot gone through any theory )</p>

<p>update 
I get following erros on the console</p>

<pre><code>[2013-01-12 12:32:02 - TabbedActivity] res\drawable-ldpi\video-hover.png: Invalid file name: must contain only [a-z0-9_.]
[2013-01-12 12:32:02 - TabbedActivity] res\drawable-mdpi\video-hover.png: Invalid file name: must contain only [a-z0-9_.]
[2013-01-12 12:32:02 - TabbedActivity] res\drawable-xhdpi\video-hover.png: Invalid file name: must contain only [a-z0-9_.]
[2013-01-12 12:32:02 - TabbedActivity] res\drawable-hdpi\video-unhover.png: Invalid file name: must contain only [a-z0-9_.]
[2013-01-12 12:32:02 - TabbedActivity] res\drawable-ldpi\video-unhover.png: Invalid file name: must contain only [a-z0-9_.]
[2013-01-12 12:32:02 - TabbedActivity] res\drawable-mdpi\video-unhover.png: Invalid file name: must contain only [a-z0-9_.]
[2013-01-12 12:32:02 - TabbedActivity] res\drawable-xhdpi\video-unhover.png: Invalid file name: must contain only [a-z0-9_.]
</code></pre>
