(function(){

    var r = /\d+/g;

    String.prototype.paramEncode = function(){
        if (!/^[a-zA-Z\d\_\-\.\,]*$/.test(this)) {
            var c = new Array(this.length);
            for(var i = 0; i < this.length; i++)
                c[i] = this.charCodeAt(i);
            return '_ENC_' + c.join('A');
        } else {
            return this;
        }
    }

    String.prototype.paramDecode = function(){
        if (this.substr(0, 5) != '_ENC_') return this;
        var c = this.substr(5).match(r);
        return String.fromCharCode.apply(null, c);
    }

    String.prototype.endsWith = function(suffix) {
        return this.indexOf(suffix, this.length - suffix.length) !== -1;
    };

    String.prototype.removeEnd = function(suffix) {
        if (this.endsWith(suffix)) {
            return this.substr(0, this.length - suffix.length);
        } else {
            return this;
        }
    };

    String.prototype.htmlEncode = function() {
        return this.replace(/&/g, "&amp;").replace(/</g, "&lt;").replace(/>/g, "&gt;").replace(/\"/g, "&quot;");
    }

    String.prototype.htmlDecode = function() {
        return this.replace(/&quot;/g, "\"").replace(/&gt;/g, ">").replace(/&lt;/g, "<").replace(/&amp;/g, "&");
    }

    String.prototype.hashCode = function() {
        var hash = 0, i, chr;
        if (this.length === 0) return hash;
        for (i = 0; i < this.length; i++) {
            chr = this.charCodeAt(i);
            hash = ((hash << 5) - hash) + chr;
            hash |= 0;
        }
        return hash;
    }

})();