function MsPowerpoint_SearchInSlides($str, $returnFirstFound = true) {

		// init the list of slides
		$this->MsPowerpoint_InitSlideLst(); // List of slides

		// build the list of files in the expected structure
		$files = array();
		foreach($this->OpenXmlSlideLst as $i=>$s) $files[$i+1] = $s['idx'];

		// search
		$find = $this->TbsSearchInFiles($files, $str, $returnFirstFound);

		return $find;

	}