Call .js file in UpdatePanel from CodeBehind

[jvjvjv_]

I am have been trying to teach myself ASP.NET and Javascript for a project and have been stuck on one problem for literally dozens of hours now.

I found a really nice javascript drag-and-drop list online, copied the source offered and split the css into a .css file, the javascript into a .js file and the HTML and reference into my asp.net page. It worked perfectly. Great!

Next, I replaced the javascript list with a static HTML list populated with the same data, wrapped it in an UpdatePanel and set up an "edit order" button to swap the static list's HTML for the javascript list's HTML when the button is pressed.

No Dice!

First, the initial runtime would throw up javascript errors explaining that certain objects could not be found. For example:

Microsoft JScript runtime error: Unable to get value of the property 'getElementsByTagName': object is null or undefined

Understood, because the elements aren't actually there yet. So I removed my reference to the .js in the main header and tried to register the .js file when the update panel is changed instead.

This is my problem.

Most explanations online have focused onRegisterClientScriptBlock, or RegisterStartupScript, or RegisterClientScriptInclude, or myLiteral and I can't get any of them to work. I also find that lots of online explanations are for running a single javascript function, whereas the script I am trying to get working has 700 lines-worth of them! Do I have to reference them all individually?

Sorry for the, no doubt, newbish question. I waited to ask until I had shouted at the screen with sufficient vitriol to warrant begging for help!

Thanks and regards.