Getting error like are you missing an assembly reference in my program

i am using this code in .net framework 3.5 , for creating a grammar using visual studio 2010 professional in win 7 but i am getting errors like The type or namespace name 'Speech' does not exist in system (are you missing a using directive or an assembly reference.

The type or namespace name 'SpeechRecognitionType' could not be found (are you missing a using directive or an as开发者_C百科sembly reference,

similarly others like type linq does not exist are you an missing an assembly refernce.

`using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms; using System.Speech.Recognition; using System.Threading;

namespace SpeechRecogTest { public partial class Form1 : Form { SpeechRecognitionEngine sr = new SpeechRecognitionEngine();

    public Form1()
    {
        InitializeComponent();
    }

    private void Form1_Load(object sender, EventArgs e)
    {
        //Create grammar
        Choices words = new Choices(); 
        words.Add("Hi");
        words.Add("No");
        words.Add("Yes");

        Grammar wordsList = new Grammar(new GrammarBuilder(words));

        wordsList.SpeechRecognized += new EventHandler<SpeechRecognizedEventArgs>(rec_SpeechRecognized);
        sr.LoadGrammar(wordsList);

    }

    void rec_SpeechRecognized(object sender, RecognitionEventArgs e)
    {
        MessageBox.Show(e.Result.Text);
    }
}

}`

As it asks "are you missing a using directive or an assembly reference"? You're not missing the using directive, therefore it's likely you're missing the assembly. Right-click on "References" => "Add Reference" => NET tab => System.Speech dll.