On a web page, we often see several interrelated drop-down menu selection boxes. When the visitor selects an option in the first drop-down selection box, the content in the second drop-down selection box changes. This situation often occurs for web developers. For example, we have to choose a region name, then first select the provincial name, then select the city name in the province: How to use the JavaScript script to implement the above functions. Implementation principles The functions above, actually to achieve dynamically generating page content. This requires support for Internet Explorer 4.0 and dynamic HTML technology. First create an empty SELECT list, and then populate it with the appropriate Option element as needed. In order to avoid input too much redundant code, you can assign an identity and value corresponding to the option, and then you can reference it to complete the fill. Related code Note that DHTML code is only available for Internet Explorer 4.0 or above, so if you want to consider more user-end browser types, add additional discriminant code to guide users to other pages.
