Some attributes are not available when "Minimum SDK" is less than the Build SDK
<p>I just faced to a weired problem in Android. That is, I created my project in eclipse using default settings. Eclipse has applied "Android 2.3.3 (API10) as the "Build SDK" and "API8:Android 2.2 (Froyo)" as the "Minimum required SDK. </p>

<p>However, I asked a question <a href="http://stackoverflow.com/questions/13014440/setting-up-textboxes-in-same-straight-line/13014536#comment17662128_13014536">here</a> and they have asked me to use the attribute "<code>android:layout_toRightOf</code>" but that attribute wasn't available!! Following were the attributes available which starts with <code>android:layout_</code>, they are width, height, weight, gravity, margin, marginLeft, marginTop, marginRight and marginBottom.</p>

<p>However, then I opened another project with "Android 2.3.3 (API10) as the "Build SDK" and  the same as the "Minimum required SDK". Now, those attributes are there!!</p>

<p>Why is this? Do I have to select the same API as the build sdk and minimum required sdk? Please help! </p>

<p><strong>EDIT</strong></p>

<p>Following code has those attributes, which didn't appear when I am trying to use at the first time</p>

<pre><code>&lt;RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical"
 &gt;

&lt;TextView 
    android:id="@+id/firstTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/firstNumber"
    android:alignParentLeft="true"
    android:alignParentTop="true"
    /&gt;

&lt;EditText 
    android:id="@+id/firstNumberTxt"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:toRightOf="@+id/firstTextView"
    android:marginLeft=30dp 
    /&gt;

&lt;TextView 
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="@string/secondNumber"
    android:alignLeft="@+id/firstTextView"
    android:below="@+id/firstTextView"
    /&gt;

&lt;EditText 
    android:id="@+id/secondNumberTxt"
    android:layout_width="match_parent"
    android:layout_height="wrap_content" 
    android:alignLeft="@+id/firstNumberTxt"
    android:below="@+id/firstTextView"
    /&gt;

     &lt;RadioGroup
         android:id="@+id/radioGroup"
         android:layout_width="wrap_content"
         android:layout_height="wrap_content"
         android:orientation="horizontal"
         &gt;

         &lt;RadioButton 
             android:id="@+id/sum"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="@string/sum"
             /&gt;

         &lt;RadioButton 
             android:id="@+id/min"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="@string/min"
             /&gt;

         &lt;RadioButton 
             android:id="@+id/max"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="@string/max"
             /&gt;

         &lt;RadioButton 
             android:id="@+id/dev"
             android:layout_width="wrap_content"
             android:layout_height="wrap_content"
             android:text="@string/dev"
             /&gt;
     &lt;/RadioGroup&gt;
</code></pre>
