We have recently installed GPS locators in some of our salesman's vans and have had a team taking GPS locations (X and Y) of our Customers with the objective of showing the van's route taken and the customers he serviced on a map.

We have GIS software that will do most of what we want but I deceided it would be a wizard excersise to see if I could write a VB .NET program that we could use to plot customers on a map depending on various information from our databases. For example, show me all the customers who bought Omo 125G on a Thursday from a salesman with a P in his name.

I have a big map of our city scanned as a JPG file and I have the Longitude and Latitude of the top left and bottom right of the map. Unfortunately the GPS locations we got for the customers are in X and Y coordinates. Numbers like X=21.50706232 Y=39.19164042. I don't have the X and Y coordinates of the top left and bottom right of the map. I was hoping that could be calculated.

What I don't know is how to calculate the position on the PictureBox holding the map using the data I have. How do I get to the pixel offset, preferable as a Point structure using the data that I have so I can do a DrawElipse to mark the position.

I haven't got much hair left so any help would be greatly appreciated.

Kevin Bell