var TextCounter = Class.create();
TextCounter.prototype = {
    initialize: function(textareaid, inputid, maxLength, colorValid, colorInvalid) {
        this.maxLength = maxLength;
        this.textarea = $(textareaid);
        this.input = $(inputid);
		this.maxLength = maxLength;
		this.input.innerTEXT = maxLength;
        Event.observe(this.textarea, 'keyup', this.checkChars.bindAsEventListener(this));
        Event.observe(this.textarea, 'keydown', this.checkChars.bindAsEventListener(this));
        this.colorValid = colorValid;
        this.colorInvalid = colorInvalid;
        this.checkChars();
    },
    checkChars: function(e) {
        var includeBreaksInCount = true; // false = don't count a return (\r or \n) in the count.
        var charCount = this.textarea.value.length;
        var breaks = 0;
        if (!includeBreaksInCount) {
            var lines = this.textarea.value.split('\n');
            breaks = lines.length;
            // check for /r at the end of the lines
            for (var i=0; i<lines.length; i++) {
                var line = lines[ i ];
                if (line.charCodeAt(line.length-1) == 13)
                    breaks++;
            }
        }

        // check if over limit
        if ((charCount-breaks) > this.maxLength) {
            this.textarea.value = this.textarea.value.substring(0, (this.maxLength + breaks) );
        }

        // update counter
        if (this.input) {
            if ((charCount-breaks) > this.maxLength) {
				this.input.style.color = this.colorInvalid;
                this.input.innerHTML = 0;
            } else {
				this.input.style.color = this.colorValid;
                this.input.innerHTML = (this.maxLength + breaks) - charCount;
            }
        }
    }
}