Javascript string include method Object doesn't support this property or method

Thanks Leo.
Might anyone know an online resource that constitutes an authorative source for the version of jscript in use on DOpus?
I have looked

  1. DOpus > Help > About
  2. I had reason to look in the jscript code in this post Script to perform multiple Regular Expressions.
    I thought that in the comments there that references to some microsoft or other URL existed but not there I must be mistaken. In that same post is a sample script to execute multiple regular expression file renames. It uses the
    str.toLowerCase(); and
    str.replace()
    methods in that code obviously successfully.
  3. I have tried these also no joy
    str.find(); and
    str.Find()

Any help much appreciated