script che non funziona con firefox

[lorymacri]

Ciao ragazzi,

ho un problema con il seguente script che non mi funziona con firefox ma non so il motivo...

/***********************************************
	* Disable select-text script- � Dynamic Drive (www.dynamicdrive.com)
	* This notice MUST stay intact for legal use
	* Visit http://www.dynamicdrive.com/ for full source code
	***********************************************/

	//form tags to omit in NS6+:
	var omitformtags=["input", "textarea", "select"]

	omitformtags=omitformtags.join("|")

	function disableselect(e){
	if (omitformtags.indexOf(e.target.tagName.toLowerCase())==-1)
	return false
	}

	function reEnable(){
	return true
	}

	if (typeof document.onselectstart!="undefined")
	document.onselectstart=new Function ("return false")
	else{
	document.onmousedown=disableselect
	document.onmouseup=reEnable
	}