为什么实例化的datacontext的属性和方法的Intellisense没有显示？

I have a web application project within VS 2008 and I have created a Linq to SQL file onto which I have dragged a table from my data base. The data context is created fine but when I instantiate an object of this type the only item I get showing on the Intellisense for it is the class based on the table I dragged onto the designer and even on this I get no Intellisense if I put a dot after it. Has anyone any idea why I am not seeing all the methods for this datacontext (i.e. SubmitChanges etc).I have a web application project within VS 2008