string escaped ( copied from YUI library )

escaped.js

/**
    Returns a copy of the specified string with special regular expression
    characters escaped, allowing the string to be used safely inside a regex.
    The following characters, and all whitespace characters, are escaped:
 
        - $ ^ * ( ) + [ ] { } | \ , . ?
 
    If _string_ is not already a string, it will be coerced to a string.
 
    @method regex
    @param {String} string String to escape.
    @return {String} Escaped string.
    @static
    **/
    function regex(string) {
        // There's no need to escape !, =, and : since they only have meaning
        // when they follow a parenthesized ?, as in (?:...), and we already
        // escape parens and question marks.
        return (string + '').replace(/[\-$\^*()+\[\]{}|\\,.?\s]/g, '\\$&');
    }