title: ConnectionString in LinqToSQL
body: <p>i wrote a sample with c# but when i use relative connectionstring it doesnt save data to database and doesnt make any exception or error even:</p>
  
  <pre><code>private void AddButton_Click(object sender, EventArgs e)
  {
      using (DataBaseModelDataContext DB = new DataBaseModelDataContext(@"Data Source=.\SQLEXPRESS;AttachDbFilename=|DataDirectory|\DataBase.mdf;Integrated Security=True;User Instance=True"))
      {
          Person person = new Person { Name=NameField.Text,LastName=LastNameField.Text};
          DB.Persons.InsertOnSubmit(person);
          DB.SubmitChanges();
          MessageBox.Show("Add successfully");
      }
  }
  </code></pre>
  
  <p>but when i change connection string it works:</p>
  
  <pre><code>using (DataBaseDataContext DB = new DataBaseDataContext(@"Data Source=.\SQLEXPRESS;AttachDbFilename=C:\Users\Herald\Documents\Visual Studio 2010\Projects\LinqToSql\LinqToSql\DataBase.mdf;Integrated Security=True;Connect Timeout=30;User Instance=True")
  </code></pre>
  
  <p>but i need to use relative connection string what should i do:</p>