With javascript you can alter the different elements within the HTML page, which is great when you are doing things like AJAX and you just want to alter one part of the page and not the whole page.
All you need to do is to get the element that you want to “talk” to and then alter that HTML tags element parts, so lets say that you have a HTML P tag
you can get that element within a variable for javascript to talk to it via
var elem = document.getElementById("hideme");
and now you can alter all parts of that HTML P tag, e.g. the style, the inner HTML text (which is the text within the <p>innerHTML</p> tags) which gives you allot more things to do on the page that allows more of a desktop feel to the site over a static page that you need to send back and forth to the server.
Of course you cannot alter any internal parts of the HTML tag that do not exist e.g. for the HTML Input there is no innerHTML because it only has a value (the text within the input box) so if you try and do that some web browsers will error/stop/or just ignore.
Here is the full source code that will alter a HTML P style to red and also the innerHTML, and also a lower one will hide and then show the text within a HTML P tag whilst altering the link to show either “click here to hide me”/”click here to show me”, which once again helps users to now what to do.
Click me
some text within the paragraph
hideme after the click below
you can alter the style e.g. style.display = value
and also alter the innerHTML - as I am altering the HTML A tag below text from hide/show me
click to hide me
with using more javascript on pages, you need to have a way of keeping details of the updates on a page if you browse away from that page and come back which is where some problems could arise. So you just need to freshen up on your HTML tags and what they are capable of doing and have fun 🙂