Error: No resource found that matches the given name (at 'theme' with value '@style/AppTheme')

![give me error : ( ]

i tryed every thing ... [2014-11-15 17:56:06 - LoginActivity] C:\Users\Different\workspace\LoginActivity\AndroidManifest.xml:15: error: Error: No resource found that matches the given name (at 'theme' with value '@style/AppTheme'). [2014-11-15 17:56:06 - LoginActivity] [2014-11-15 17:56:07 - LoginActivity] C:\Users\Different\workspace\LoginActivity\AndroidManifest.xml:15: error: Error: No resource found that matches the given name (at 'theme' with value '@style/AppTheme'). [2014-11-15 17:56:07 - LoginActivity] [2014-11-15 17:56:10 - LoginActivity] C:\Users\Different\workspace\LoginActivity\AndroidManifest.xml:15: error: Error: No resource found that matches the given name (at 'theme' with value '@style/AppTheme'). [2014-11-15 17:56:10 - LoginActivity] [2014-11-15 17:56:12 - LoginActivity] C:\Users\Different\workspace\LoginActivity\AndroidManifest.xml:15: error: Error: No resource found that matches the given name (at 'theme' with value '@style/AppTheme'). [2014-11-15 17:56:12 - LoginActivity] im using eclipse "windows 7"

the error is in this line android:theme="@style/AppTheme" >

in androidmanifest.xml , this is the whole code `

<uses-feature
    android:name="android.hardware.microphone"
    android:required="false"/>

<uses-permission android:name="android.permission.INTERNET"/>
<uses-permission android:name="android.permission.RECORD_AUDIO"/>
<uses-permission android:name="android.permission.MODIFY_AUDIO_SETTINGS"/>
<uses-permission android:name="android.permission.READ_PHONE_STATE"/>
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE"/>

<application
    android:allowBackup="true"
    android:icon="@drawable/icon"
    android:theme="@style/AppTheme" >
    <activity
        android:name=".LoginActivity"
        android:label="Log In">
        <intent-filter>
            <action android:name="android.intent.action.MAIN" />
            <category android:name="android.intent.category.LAUNCHER" />
        </intent-filter>
    </activity>
    <activity
        android:name=".CallActivity"
        android:label="Make a Call"
        android:screenOrientation="portrait">
    </activity>
</application>

`