#include <MsgBoxConstants.au3> ; to declare the Constants of MsgBox
Local $sRegex = "(?ism)<p(?: [^>]+)?>((?:(?!<\/?p[ >]).)*)<\/p>"
Local $sString = "<p style="text-align: right;">" & @CRLF & _
" <p style="text-align: center;">" & @CRLF & _
" <p style="text-align: left;">" & @CRLF & _
" <p style="text-align:center;">" & @CRLF & _
" leave this content" & @CRLF & _
" </p>" & @CRLF & _
" </p>" & @CRLF & _
" </p>" & @CRLF & _
"</p>"
Local $sSubst = "$1"
Local $sResult = StringRegExpReplace($sString, $sRegex, $sSubst)
MsgBox($MB_SYSTEMMODAL, "Result", $sResult)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm