Android error: You must specifiy a valid layout reference. The layout ID. in elcipse

[covehost]

I have been working with elcipse for a couple of weeks now. My code has functioned properly but all of a sudden it has stopped working. I get this error,main.xml: You must specifiy a valid layout reference. The layout ID @layout/required is not valid.my XML code\[code\]<?xml version="1.0" encoding="utf-8"?><ScrollView xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="fill_parent" ><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="fill_parent" android:layout_height="wrap_content" androidrientation="vertical"> <!-- select between BIN or auction --> <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="wrap_content" android:gravity="center_horizontal" androidrientation="horizontal" > <Button android:id="@+id/AuctionButton" android:layout_marginLeft="82dp" android:layout_width="119dp" android:layout_height="wrap_content" androidnClick="showAuctionOptions" android:text="Auction" /> <Button android:id="@+id/BINButton" android:layout_marginLeft="-2dp" android:layout_width="119dp" android:layout_height="wrap_content" androidnClick="showAuctionOptions" android:text="Buy it now" /> </LinearLayout> <include android:id="@+id/cell1" layout="@layout/required"/> <include android:id="@+id/cell2" layout="@layout/gray_line" /> <!--** Show if Buy it now is selected **--> <include android:id="@+id/cell3" layout="@layout/buyitnow" /> <!-- ** End Buy it now display ** --> <!--** Show if auction selected ** --> <include android:id="@+id/cell4" layout="@layout/auction" /> <include android:id="@+id/cell5" layout="@layout/gray_line" /> <include android:id="@+id/cell6" layout="@layout/addons" /> <include android:id="@+id/cell7" layout="@layout/calculate" /> </LinearLayout></ScrollView>\[/code\]the error is with the first include, however if I remove that, I just get an error with the second include. If I remove all of the include, I get a 'could not resolve R' error within my java code.What I have tried,

• cleaning the project
• restarting eclipse
• rebooting my computer

this is my AndroidManifest XML file,\[code\]<?xml version="1.0" encoding="utf-8"?><manifest xmlns:android="http://schemas.android.com/apk/res/android" package="toggler.state" android:versionCode="1" android:versionName="1.0" > <uses-sdk android:minSdkVersion="10" /> <application android:icon="@drawable/ic_launcher" android:label="@string/app_name"> <activity android:name=".TogglerActivity" android:label="@string/app_name"> <intent-filter> <action android:name="android.intent.action.MAIN" /> <category android:name="android.intent.category.LAUNCHER" /> </intent-filter> </activity> </application></manifest>\[/code\]none of which have worked.Could anyone help please?Thanks