How to inject HTML and JavaScript into page?

How to write JavaScript on page load?

I'm going to make a calculator on JavaScript.

Can someone tell me ? For example, when you go to a page it shows a div (which looks like a calculator) and there are different functions in this calculator. If you click a button, the div will change to another calculator. Then if you click another button, it will change back to the original div. But if you open the JavaScript file, write codes to make it work, and then close the file, what will happen to the div on that page?
Thank you for your help. The answer to your question is yes. You can create as many scripts as you wish in your document and place them in the head section of the page, then when the page loads, they are all run in the order they are listed in the head tag. However, this does not mean the following:

The script execution order will be the same as the script tag order (as seen. By HTML rendering). The order that the script tags are encountered in by a browser is not. Necessarily in the same order as the scripts listed in the head tag.

How to inject HTML and JavaScript into page?

I've spent a long time reading about the various topics in ASP.

NET and WebMatrix (and of course JavaScript), and now I'm finally able to figure out how to insert HTML and JavaScript into a page. Unfortunately I've yet to find any documentation on how to do this, so here is my question:
How can I insert an HTML element onto a page? I'm assuming this is done through the "inject" method as described in ScottGu's post over on MSDN, but so far it has not worked for me. This is the code I have at the moment: Response. When I run it just writes the string I passed to the Response.Write() method.

Thanks in advance.
I think the "insert html" section of the linked post is a good start. It takes a bit to get used to the syntax though, try playing around with it a little to see what I mean, something like: string user = Context.

Can Chrome extensions inject JavaScript?

The following seems to be the consensus answer, but I'm not seeing that as a clear Yes or No statement.

Can we make it as a clear Yes or No statement? I have an existing solution that needs to support the injection of Javascript into the page on which it is running. I'd like to do this through a Chrome extension instead of having to create an add-on.

Yes, there is functionality in the Chrome Extension API that allows extensions to inject JavaScript code. See Basically, there are 3 methods (ContentScript, Inject and ClientScript) in the Extension API that allow you to inject JavaScript code into a page. You can read more about them here: For your example, you'd want to call ClientScript on a page object (eg document) to inject the JS code into that document.