Unable to use android.support.v7.widget.toolbar

I'm trying to change status bar color in my application. For this I set MainActivity.java theme to "Theme.NoTitleBar.Fullscreen". Now, in my activity_main.xml, I create a frame layout followed by action bar. The project seems fine without errors but when I run it, the app crashes. Logcat shows something like.."unable to find class android.support.v7....". I added appcompat v7 library to my project but not sure whether i done it correctly. I'm a beginner, please help me.

activity_main.xml

<LinearLayout 
    xmlns:android="http://ift.tt/nIICcg"
    xmlns:tools="http://ift.tt/LrGmb4" 
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    tools:context="com.example.saregama.MainActivity" 
    android:orientation="vertical"
    android:background="#1A1A1A">


    <FrameLayout

      android:layout_width="match_parent"
      android:layout_height="25dp"
      android:background="#3D3D99">

  </FrameLayout>



 <android.support.v7.widget.Toolbar
    xmlns:android="http://ift.tt/nIICcg"
    xmlns:app="http://ift.tt/GEGVYd"
    android:id="@+id/toolbar"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="#3D3D99"
    ></android.support.v7.widget.Toolbar> 



 <ListView
        android:dividerHeight="1dp"
        android:divider="#000000"
        android:padding="10dp"
        android:layoutAnimation="@anim/layout_bottom_to_top_slide"
        android:smoothScrollbar="true"
        android:animationCache="false"
        android:scrollingCache="false"
        android:id="@+id/product_list"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="@string/hello_world" /> 


</LinearLayout>