fixed LightBox example

example/src/screens/FirstTabScreen.js

       screen: "example.LightBoxScreen",
       style: {
         backgroundBlur: "dark"
-      }
+      },
+      passProps: {
+        greeting: 'hey there'
+      },
     });
   }
 

example/src/screens/LightBoxScreen.js

 import React, {Component} from 'react';
 import {
+  StyleSheet,
   Text,
   View,
-  ScrollView,
   TouchableOpacity,
-  StyleSheet
+  Dimensions
 } from 'react-native';
 
 export default class LightBoxScreen extends Component {
   }
   render() {
     return (
-      <View style={{width: 300, height: 200, padding: 20}}>
-
-        <Text>
-          This is a LightBox
+      <View style={styles.container}>
+        <Text style={styles.welcome}>
+          This is a LightBox!
         </Text>
-
-        <TouchableOpacity onPress={ this.onDismissPress.bind(this) }>
+        {
+          this.props.greeting &&
+            <Text style={[styles.welcome, {fontSize: 16, marginTop: 20}]}>
+              {this.props.greeting}
+            </Text>
+        }
+        <TouchableOpacity onPress={() => this.onDismissPress()}>
           <Text style={styles.button}>Dismiss</Text>
         </TouchableOpacity>
-
       </View>
     );
   }
   }
 }
 
-const styles = StyleSheet.create({
+var styles = StyleSheet.create({
+  container: {
+    flex: 1,
+    width: Dimensions.get('window').width * 0.8,
+    justifyContent: 'center',
+    alignItems: 'center',
+    backgroundColor: 'white',
+    borderRadius: 10
+  },
+  welcome: {
+    fontSize: 20,
+    textAlign: 'center',
+    margin: 10,
+  },
+  instructions: {
+    textAlign: 'center',
+    color: '#333333',
+    marginBottom: 5,
+  },
   button: {
     textAlign: 'center',
     fontSize: 18,