function preg_quote( str ) {	// Quote regular expression characters
	// 
	// + original by: booeyOH
	// + improved by: Ates Goral (http://magnetiq.com)
	return str.replace(/([\\\.\+\*\?\[\^\]\$\(\)\{\}\=\!\<\>\|\:])/g, "\\1ドル");
}

preg_quote("40ドル");

preg_quote("*RRRING* Hello?");

preg_quote("\\.+*?[^]$(){}=!<>|:");