libraries/tbs/plugins/tbs_plugin_opentbs.php
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);

	}
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);

	}
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().