I was wondering whether someone could take a look at my code and give me some points as to how I could optimise it? It is fairly slow when it runs on my desktop so I haven't even bothered running it on my PPC yet! Basically the program takes some initial lat/long data from a GPS (but for the purposes of testing, from 2 text boxes on the form) and compares this to a list of UK postcodes and their lat/longs read from the data file. It then works out which postcode is closest to the initial lat/long data. I have only included a very small part of the data file as an example as I do not think I am allowed to distribute the full data set. I am reading the text file a line at a time. Firstly, I couldn't see a way in the help to read part of a line (as in a comma delimited file) so my program has to iterate through each character in the line to check for commas. I'm sure there is a much more efficient way of doing this! Secondly, I kept getting errors when I tried to peform maths functions on the data I read in. Ideally I need the numeric data to be stored as a Double, but since there are no functions to convert data types (that I could see) I think my program was treating the data as a String which was causing me errors. To overcome this I have used the Decimal library throughout my code which I'm sure is horribly inefficient given the number of calculations involved. The program works as-is but as I said is incredibly slow... any help in speeding it up would be much appreciated!