How to make js return href inside id?

Question

JavaScript

Here is a piece of code, how to refer to href? you need to find it and replace it with js methods.
Please, help!
Tried GetElementById - doesn't help!
Example:

<li id="l_pr" class="">
  <a href="/id200986" onclick="return nav.go(this, event, {noback: true, params: {_ref: 'left_nav'}});" class="left_row">
</li>

Answer 1

<a href='url' id='myId'>link</a>

var el = document.querySelector('#myId');
var href = el.getAttribute('href'); //получить href вашей ссылки
el.setAttribute('href', 'newurl'); //установить новый href

https://learn.javascript.ru/attributes-and-custom-... - more details

Answer 2

An example is here:

<li id="l_pr" class="">
  <a href="/id20026986" onclick="return nav.go(this, event, {noback: true, params: {_ref: 'left_nav'}});" class="left_row">
</li>

In this case, it returns null if you do as you suggested...