Toast.makeText(this, "Bitte nur Zahlen eingeben!", Toast.LENGTH_LONG).show();

<!--
/* //device/apps/common/res/layout/alert_dialog.xml
**
** Copyright 2006, The Android Open Source Project
**
** Licensed under the Apache License, Version 2.0 (the "License");
** you may not use this file except in compliance with the License.
** You may obtain a copy of the License at
**
**     http://www.apache.org/licenses/LICENSE-2.0
**
** Unless required by applicable law or agreed to in writing, software
** distributed under the License is distributed on an "AS IS" BASIS,
** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
** See the License for the specific language governing permissions and
** limitations under the License.
*/
-->

---gekürzt---

<LinearLayout android:id="@+id/buttonPanel"
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:minHeight="54dip"
        android:orientation="vertical" >     
        <LinearLayout 
            android:layout_width="fill_parent"
            android:layout_height="wrap_content"
            android:orientation="horizontal"
            android:paddingTop="4dip"
            android:paddingLeft="2dip"
            android:paddingRight="2dip" >
            <LinearLayout android:id="@+id/leftSpacer"
                android:layout_weight="0.25"
                android:layout_width="0dip"
                android:layout_height="wrap_content"
                android:orientation="horizontal"
                android:visibility="gone" />
            <Button android:id="@+id/button1"
                android:layout_width="0dip"
                android:layout_gravity="left"
                android:layout_weight="1"
                android:maxLines="2"
                android:layout_height="wrap_content" />
            <Button android:id="@+id/button3"
                android:layout_width="0dip"
                android:layout_gravity="center_horizontal"
                android:layout_weight="1"
                android:maxLines="2"
                android:layout_height="wrap_content" />
            <Button android:id="@+id/button2"
                android:layout_width="0dip"
                android:layout_gravity="right"
                android:layout_weight="1"
                android:maxLines="2"
                android:layout_height="wrap_content" />
            <LinearLayout android:id="@+id/rightSpacer"
                android:layout_width="0dip"
                android:layout_weight="0.25"
                android:layout_height="wrap_content"
                android:orientation="horizontal"
                android:visibility="gone" />
        </LinearLayout>
     </LinearLayout>
</LinearLayout>

    public static void displayErrorMessage(CharSequence message, Context context) {
        // display error message
        AlertDialog.Builder builder = new AlertDialog.Builder(context);
        builder.setMessage(message).setCancelable(false).setPositiveButton(
                context.getResources().getText(R.string.ok),
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog, int id) {
                        // do nothing
                    }
                });
        builder.show();
    }