Windows set Environment Variables - Java path

Try two way in Eclipse IDE:

1.) Import the library project into your Eclipse workspace.
Click File > Import,
select Android > Existing Android Code into Workspace, and browse to the copy of the library project to import it.
If project not visible with checkbox try next step as see below.

2.) Click
File > New > Other
select Android > Existing Android Code into Workspace, and browse to the copy of the library project to import it.

[2013-07-06 16:10:29 - SDK Manager] [SDK Manager] Error: Error parsing the sdk.
[2013-07-06 16:10:29 - SDK Manager] [SDK Manager] Error: Failed to create C:\Program Files\android\sdk\add-ons.
[2013-07-06 16:10:29 - SDK Manager] [SDK Manager] Error: Unable to parse SDK content.

You have to create add-ons folder as admin of PC

Samsung Galaxy Ace nejlepší cena od 4 500 KCZ Kč (únor.2012)
Samsung Galaxy Ace je chytrý telefon s operačním systémem Android.
Samsung Galaxy Ace je (22.února2012) 4. nejpoužívanějším chytrým telefonem u programu Sky Map viz tabulka.

Galaxy Ace je 3.5G smartphone nabízí i quad-band GSM. Displej je 3,5 palcový TFT kapacitní dotykový LCD HVGA s (320x480) rozlišením. K dispozici je také 5 megapixelový fotoaparát s LED bleskem. Je schopny zaznamenat video v rozlišení QVGA (320x240) a VGA s (640x480) rozlišením. Ace je dodáván s 1350mAh Li-Ion baterií. Ace běží s OS Android 2.2 Froyo a lze jej upgradovat na Android 2.3.6 Gingerbread.

Samsung Galaxy Ace photo pic image

Zdroj obrázku: wikipedia

build.gradle in module have higher priority then AndrodiManifest.xml
Try this.
AndroidManifest.xml have code:

    <uses-sdk
        android:minSdkVersion="9"
        android:targetSdkVersion="23" />

build.gradle have code:

   defaultConfig {
        applicationId "cz.okhelp.words"
        minSdkVersion 9
        targetSdkVersion 19
        versionCode 107
        versionName "1.0.7"
    }

Warning in AndroidManifest.xml:
This targetSdkVersion value (23) is not used; it is always overridden by the value specified in the Gradle build script (19) less... (Ctrl+F1)
The value of (for example) minSdkVersion is only used if it is not specified in the build.gradle build scripts. When specified in the Gradle build scripts, the manifest value is ignored and can be misleading, so should be removed to avoid ambiguity.

Difference between "@+id/” and "@id/” in Android
android:id="@+id/xxx" unique identifier of view
@id/ a reference to the unique identifier

 <TextView
        android:id="@+id/first_element_id"
        .........
 />
    <TextView
        android:id="@+id/second_element_id"
        android:layout_below="@id/first_element_id"
        ..........
 />