java - Source not found! -

i'm trying write application opens window when button selected here have far:

public class androidalarm extends activity { /** called when activity first created. */ @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.main);              button codesbtn = (button)findviewbyid(r.id.imagebutton1);     codesbtn.setonclicklistener(new view.onclicklistener() {         public void onclick(view argo) {             intent = new intent(androidalarm.this, codes.class);             startactivity(i);         }     });     } } 

this have in default class, activity i'm trying start class called codes:

public class codes extends activity { /** called when activity first created. */ @override public void oncreate(bundle savedinstancestate) {     super.oncreate(savedinstancestate);     setcontentview(r.layout.codes);     } } 

it have functionality right i'm trying open it. codes.java (above) connected layout called codes.xml.

my manifest file looks this:

<?xml version="1.0" encoding="utf-8"?> <manifest xmlns:android="http://schemas.android.com/apk/res/android"   package="com.affirma.androidalarm"   android:versioncode="1"   android:versionname="1.0">       <application android:icon="@drawable/icon" android:label="@string/app_name">         <activity class =".androidalarm" android:name = ".androidalarm"                   android:label="@string/app_name" >             <intent-filter>                 <action android:name="android.intent.action.main" />                 <category android:name="android.intent.category.launcher" />             </intent-filter>         </activity>         <activity class = ".codes" android:name = ".codes" android:label="codes">         </activity>     </application> </manifest> 

when run program, start crash saying ended abruptly. when debug, breaks @ line found in androidalarm.java:

codesbtn.setonclicklistener(new view.onclicklistener() { 

it says source not found. "activitythread.preformlauncher..." anyways don't know why happening suggestions?

the error because trying find id of "imagebutton1" r.java files in r.layout.main. please make sure have imagebutton1 has been initialized , r.java contains id of same.