Can you help my friend in converting the html variable ?

Well, you do have <var></var>

Lets get philosophical.

What is a variable?
One might say it's a data holder or a pointer to a location in the memory you can read and write.

HTML input element's value property could then be a variable. By submiting a form, you serialize and send all the input names and values to a server where they get parsed added to a $_REQUEST superglobal. So you essentially convert a HTML variable to a PHP variable.

But thats not what he meant, he acutally thought html has variables 😂

Just the 'u' instead of 'you' is putting me off!

@linuxxx Lol