I dowloaded google-play-services from sdk manager and copy pasted all the code from admob samplebut it is not working. Everything seems perfect only errors produced are R can't be resolved to a variable. Here is a sample error
Error: No resource found that matches the given name (at 'text' with value '@string/load_interstitial').
Here is strings.xml file
<resources>
<string name="app_name">Google Ads SDK Sample</string>
<string name="ad_unit_id">INSERT_YOUR_AD_UNIT_ID_HERE</string>
<string name="load_interstitial">Load Interstitial</string>
<string name="interstitial_not_ready">Interstitial Not Ready</string>
<string name="banner_in_xml">Banner in XML</string>
<string name="banner_in_code">Banner in Code</string>
<string name="interstitial">Interstitial</string>
</resources>