Array

Well first load all your give postcodes into an array like
array = recordset.GetRows( Rows, Start, Fields )
Now I don't know how you query so I give you the more complex form, you may be able to streamline it further if your query is simpler.
Dim i as integer = 0
For i=0 to ubound(array)
'Query here with the postcode like
Select whatever from yourtable where postcode='" & array(i) & "'"
Next

This method can like I said be streamlined to only do one database call instead of i calls

how come?  I would need to calculate the distance the user selects and run a search for all that are nearby surely?

Please tell me theres another way because it takes ages to process the page

Sounds good, so here goes. Its quite easy really...

x1 is the longitude value for the FROM post code
y1 is the latitude value for the FROM post code
x2 is the longitude value for the TO post code
y2 is the latitude value for the TO post code

Now, all I do is calculate the differences and stuff, like this....
xdif = 69.1 * (y2 - y1)
ydif = 69.1 * (x2 - x1) * cos(y1/57.3)

Where cos is the cosine function on the value in the brackets.

Then multiply x by itself and y by itself.  Add the 2 values together and calculate the square root!
miles=SQR(xdif *xdif +ydif *ydif )

Simple!

appologies, its Access. Should have said.

Ta