Linked Dropdowns

Part 2 : Get the Script

The first thing you need to do to link two dropdowns together like this is to write the HTML for the dropdown lists. Here is the code that I used for the example (note the code in bold which is needed to link in the Javascript.

The Javascript code to link these two together is fairly straightforward as well.

To apply that exact link between two of your dropdowns simply save the Javascript as shown to a file (eg. droplist.js) and then link it into the head of your web page like this:

If you don't want to exclude blank values from the link then remove the first if statement line along with the corresponding end } on the second last line. If instead you want to exclude additional values from the link simply modify that if statement to test for all of the values to be excluded. Any values that exist in the second list and not in the first will be automatically excluded (for obvious reasons) without your needing to add code for them.