title: admin_signin Activity cannot be cast to android.app.activity
body: <p>I get the following exception:</p>
  
  <pre><code>Caused by: java.lang.ClassCastException: com.tecno.applock.admin_signin cannot be cast to android.app.Activity 
  </code></pre>
  
  <p>This is the manifest file:</p>
  
  <pre><code> &lt;?xml version="1.0" encoding="utf-8"?&gt; &lt;manifest
     xmlns:android="http://schemas.android.com/apk/res/android"
         package="com.tecno.applock"
         android:versionCode="1"
         android:versionName="1.0" &gt; &lt;uses-sdk
             android:minSdkVersion="8"
             android:targetSdkVersion="19" /&gt;    
            &lt;application
             android:allowBackup="true"
             android:icon="@drawable/ic_launcher"
             android:label="@string/app_name"
             android:theme="@style/AppTheme" 
  
            &gt;
         &lt;activity
          android:name="com.tecno.applock.MainActivity"
           android:label="@string/app_name" &gt;
          &lt;intent-filter&gt;
           &lt;action android:name="android.intent.action.MAIN" /&gt;
          &lt;category android:name="android.intent.category.LAUNCHER" /&gt;
          &lt;/intent-filter&gt;
         &lt;/activity&gt;
         &lt;activity
         android:name="admin_signin"&gt;&lt;/activity&gt;
         &lt;activity
         android:name="create_guest"&gt;&lt;/activity&gt;
         &lt;activity
          android:name="delete"&gt;&lt;/activity&gt;
          &lt;activity
           android:name="edit"&gt;&lt;/activity&gt;
           &lt;activity
           android:name="Welcom_admin"&gt;&lt;/activity&gt;
     &lt;/application&gt; &lt;/manifest&gt;
  </code></pre>
  
  <p>Where am I going wrong?</p>