Wrap Lines After X Number Of Characters In A Textarea But NOT In The Middle Of A Word

I have a textarea with a specific width. I have wrap="off" set because I don't want to force my users to wrap if they don't want to. The reason for this is because this textarea is where the user is typing an email message. However I have a background image set on the textarea with a verticle line going down the textarea which indicates to the user the "Recommend Width"What I want to do is provide them with a link to click on which says something like "Wrap Lines" and when they click on it, the text within the textarea would wrap to the "Recommended Width" line in the background image. The maximum length of a line should be 53 characters when they click on "Wrap Lines" link.So I did some searching around and the code I came up with is:

Code:
function showLines(max, text) {
max--;
text = "" + text;
var temp = "";
var chcount = 0;

[Code].....