Linked Drop Down Boxes
"How can I have two drop down boxes setup so that when the user selects an item from the first drop down it changes the options in the second drop down?"
This is one of the most commonly asked questions I see. There are several wasy to perform this function which one works best for you is dependant on a number of factors, but the biggest issue is the amount of data that needs to be included in the drop downs.
If you have only a small number of possible options, then it probably makes sense to load all of the possibilities into memory when the page loads and not have to go back to the server when the user makes a selection. On the other hand if you have a large number of options then it makes more sense to connect to the server and retrieve the options when the user makes a selection.
Here I have a number of methods using both of these options
| Title | Language | Description |
| Linked Dynamic Drop Down Boxes | ASP | This example will show how to create a dynamic Pull-Down box that will update the options in a second Pull-Down box when the first Pull-Down box has an item selected. This is the ASP method of doing this. |
| Multi-Level Linked Dynamic Drop Down Boxes | ASP | This example will perform basically the same function as the previous example, but it goes a step further in the number of drop downs used. The code can be modified to link as many drop down boxes as required |
| Linked Dynamic Drop Down Boxes | JS | This example will show how to create a dynamic Pull-Down box that will update the options in a second Pull-Down box when the first Pull-Down box has an item selected. This JavaScript version of this example does not require a page reload. |
| Multi-Level Linked Dynamic Drop Down Boxes | JS | This example will perform basically the same function as the previous example, but it goes a step further in the number of drop downs used. The code can be modified to link as many drop down boxes as required |
| Multi-Level Linked Dynamic Drop Down Boxes | AJAX | This example shows a newer method of performing linked drop-down boxes with the benefits of both the ASP and Javascript methods. |