implemented using_alert_dialog

using_alert_dialog/lib/main.dart

@@ -0,0 +1,40 @@
+import 'package:flutter/material.dart';
+
+void main() {
+  runApp(new MaterialApp(
+    home: new MyHome(),
+  ));
+}
+
+class MyHome extends StatefulWidget {
+  @override
+  MyHomeState createState() => new MyHomeState();
+}
+
+class MyHomeState extends State<MyHome> {
+  // Generate dialog
+  AlertDialog dialog = new AlertDialog(
+      content: new Text(
+    "Hello World!",
+    style: new TextStyle(fontSize: 30.0),
+  ));
+
+  @override
+  Widget build(BuildContext context) {
+    return new Scaffold(
+        appBar: new AppBar(
+          title: new Text("Using Alert Dialog"),
+        ),
+        body: new Container(
+          child: new Center(
+            child: new RaisedButton(
+                child: new Text("Hit to alert!"),
+                // On press of the button
+                onPressed: () {
+                  // Show dialog
+                  showDialog(context: context, child: dialog);
+                }),
+          ),
+        ));
+  }
+}