The onchange option in the drop-down box triggers a text box value change.

 

 

Change the value of the drop-down list to trigger a text box value change or make the value of the text box equal to the value currently selected in the drop-down list. There are usually several methods,

One is to refresh the page with post submitted in form;

One method is to use JS functions. Now we only need one sentence to describe one method.CodeYou can do the following:

 

<Select name = "Sel" onchange = "document. All. bitrate. value = Document. All. Sel. Options [document. All. Sel. selectedindex]. value;">
<Option value = "768"> 768 Kbps </option>
<Option value = "512" selected> 512 kbps </option>
<Option value = "384"> 384 kbps </option>
</SELECT>
<Input name = "bitrate" type = text class = "input" value = "512" size = "8" Title = "bit rate set in the system"> kbps

Http://maie.name/article/26.htm

Note that the above method can be controlled without placing it in the form, and the selected value can be enclosed in brackets with "[document. All. Sel. selectedindex!