android - onClick method issue -

ok, going through tutorial of "myfirstapp" on devoloper.android.com site. on last tutorial , have did first chapter can sorta say. thing is, @ end of "start activity" lesson, @ end tells run app. when run it, appears clickable button on emulator, when click it, gets runtime error , forces close. have tried research on this, not clue on going on. error is: java.lang.illeglstateexception: not find method sendmessage(view) in activity class com.example.myfirstapp.mainactivity onclick handler on view class on android.widet.b going show code this:

mainactivity:

package com.example.myfirstapp; import android.os.bundle; import android.app.activity; import android.content.intent; import android.view.menu; import android.view.view; import android.widget.edittext;  public class mainactivity extends activity {     public final static string extra_message = "com.example.myfirstapp.message";          /** called when user clicks send button */     public void sendmessage(view view) {         intent intent = new intent(this, displaymessageactivity.class);         edittext edittext = (edittext) findviewbyid(r.id.edit_message);         string message = edittext.gettext().tostring();         intent.putextra(extra_message,  message);         startactivity(intent);         // in response button     }      @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);         setcontentview(r.layout.activity_main);     }      @override     public boolean oncreateoptionsmenu(menu menu) {         // inflate menu; adds items action bar if present.         getmenuinflater().inflate(r.menu.main, menu);         return true;     }  } 

activity_display_message:

<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:paddingbottom="@dimen/activity_vertical_margin"     android:paddingleft="@dimen/activity_horizontal_margin"     android:paddingright="@dimen/activity_horizontal_margin"     android:paddingtop="@dimen/activity_vertical_margin"     tools:context=".displaymessageactivity" >      <textview         android:layout_width="wrap_content"         android:layout_height="wrap_content"         android:text="@string/hello_world" />  </relativelayout> 

displaymessageactivity.java:

package com.example.myfirstapp;  import android.annotation.suppresslint; import android.annotation.targetapi; import android.app.actionbar; import android.app.activity; import android.content.intent; import android.os.build; import android.os.bundle; import android.support.v4.app.navutils; import android.view.menuitem; import android.widget.textview;  public class displaymessageactivity extends activity {      @suppresslint("newapi")     @override     protected void oncreate(bundle savedinstancestate) {         super.oncreate(savedinstancestate);          // message intent         intent intent = getintent();         string message = intent.getstringextra(mainactivity.extra_message);          // create text view         textview textview = new textview(this);         textview.settextsize(40);         textview.settext(message);          // set text view activity layout         setcontentview(textview);          // make sure we're running on fry or higher use actionbar apis         if (build.version.sdk_int >= build.version_codes.froyo) {             // show button in action bar.             getupactionbar().setdisplayhomeasupenabled(true);         }     }      private actionbar getupactionbar() {         // todo auto-generated method stub         return null;     }      /**      * set {@link android.app.actionbar}, if api available.      */     @targetapi(build.version_codes.honeycomb)     private void setupactionbar() {         if (build.version.sdk_int >= build.version_codes.honeycomb) {             getactionbar().setdisplayhomeasupenabled(true);         }     }       @override     public boolean onoptionsitemselected(menuitem item) {         switch (item.getitemid()) {         case android.r.id.home:             // id represents home or button. in case of             // activity, button shown. use navutils allow users             // navigate 1 level in application structure.             // more details, see navigation pattern on android design:             //             // http://developer.android.com/design/patterns/navigation.html#up-vs-back             //             navutils.navigateupfromsametask(this);             return true;         }         return super.onoptionsitemselected(item);     }  } 

it looks misspelled function name in xml button onclick(). have uppercase "m" in java code

 public void sendmessage(view view) { 

and lowercase "m" in xml

<button ... android:onclick="sendmessage"/> 

to comply java standards, change in xml

 android:onclick="sendmessage"/>