Hashtable for my Distance Finder Program

Hey all i need help with the following code. Ive set up a Hashtable but it seems to have errors, i've never done one of these before. Here is some of my code as an example:

private Hashtable _distances;

_distances=new Hashtable();

Hashtable birminghamDistances=new Hashtable();
birminghamDistances.Add("Birmingham",0);
birminghamDistances.Add("Cardiff",103);
...
_distances.Add("Birmingham",birminghamDistances);

Hashtable distanceForSelectedTown = (Hashtable)_distances[txtFromTown.Text];
int distance=(int)distanceForSelectedTown[txtToTown.Text];
txtDistance.Text=distance.ToString();

I'm getting errors on line 1 (private Hastable), line 3 (_distances), line 5 (new Hashtable), line 9 (_distances) and line 11 (distances[txtFromTown.Text]

What im trying to make is this:

http://www.wrestlefury.com/distancefinder.jpg

When two places are entered in the textboxes and the calculate distance button is pressed, i want the distance to show up in the Distance Textbox. But i cant do this Hashtable, could someone please help?

Regards,

Rob

What are the errors? Are you including the System.Collections namspace?

no whats that? Ive put in brackets what the errors are. Im putting this hashtable is under btnDistance.

If your getting an error like
"the type or namespace name 'Hashtable' could not be found
add
using System.Collection;
to the start of your project.

Ive done that it still has errors, there must be something wrong with my code.