How to get websites actual HTML code by JS?
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I have a website with a form. The form is filled by user with data for example i show to user:
 
     <input type='text' value="" name="dsa" />

And he fills it with value of "3";

And he clicks button "save". Now i want to have the whole HTML of the website including values of fields. So i use:

document.documentElement.innerHTML

But i get:

     <input type='text' value="" name="dsa" />

But i want to get this:

     <input type='text' value="3" name="dsa" />

NOTICE I want to take the whole HTML of the website, not only one field. I dont know what fields will be on the website so i need a general solution.