Is it possible that you are confusing HTML paragraph tags with the newline value(s) used by your system? What you see in your browser is rendered (created, especially for you!) in response/obedience to the paragraph tags (<p> and </p>

As is, your code does nothing for me, except spew warnings and errors.

The HTML in your $text contains NO newlines. What's in the original; ie, what did your assign to $text?

Your phrase, "enter marks," coupled with your $text, and the .&enter($1) (concatenated sub call ?!??) on the replacement side the substitution leave /me confused and guessing

Update: rephrased, added (I hope) clarity to the far-too-telegraphic original.