code: static function FindStartTag(&$TxtOrObj, $Tag, $PosBeg, $Forward=true) {
  
  		if (is_object($TxtOrObj)) {
  			$TxtOrObj->FindEndTag();
  			$Txt = $TxtOrObj->GetSrc();
  			if ($Txt===false) return false;
  			$Parent = &$TxtOrObj;
  		} else {
  			$Txt = &$TxtOrObj;
  			$Parent = false;
  		}
  
  		$PosBeg = clsTinyButStrong::f_Xml_FindTagStart($Txt, $Tag, true , $PosBeg, $Forward, true);
  		if ($PosBeg===false) return false;
  
  		return new clsTbsXmlLoc($Txt, $Tag, $PosBeg, null, $Parent);
  
  	}
docs: Search a start tag of an element in the TXT contents, and return an object if it is found.
  Instead of a TXT content, it can be an object of the class. Thus, the object is linked to a copy
  of the source of the parent element. The parent element can receive the changes of the object using method UpdateParent().