Email programs are very different to Web Browsers regarding JavaScript.

One format that most email programs support to send emails in is HTML. Just because you can use HTML in emails though doesn't mean that you can also use JavaScript as well. Yes some email programs do support JavaScript but there are some very good reasons why you should disable JavaScript in your email program if it hasn't already done that for you.

JavaScript and Emails

Google Maps can display any location based on its latitude and longitude

The easiest way to specify what part of our planet that you want your Google map to display is to specify the latitude and longitude. The maps allow these to be specified to several decimal places so that you can easily move the starting position for your map to point to your house instead of your neighbour's. While this method may require some trial and error on your part to centre the map exactly where you want it is the most efficient way of defining what map to display both in terms of the code needed and the time that will be taken to position the map appropriately.

Latitude and Longitude