c#3.0 and delegate question

[CSharper]

I have a callback method where I am going to update GUI with a status.
In C#2.0 I can do the following

if (this.InvokeReq uired)
{
//Do invoke
}
else
{
//display message
}

In 3.0 I can not find the InvokeRequired. Is there something changed
in it?

Thanks.