How to setting a cookie with the contents of a textbox ?

Values stored in cookies may not have semicolons, commas, or spaces. You should use the handy "escape()" function to encode the values, and "unescape()" to retrieve them.

//Sets cookie of current value for myTextBox

function TextBoxOnchange() {

var myBox = window.document.getElementById(myTextBox");

document.cookie = "myTextBox="+ escape(myBox.value) + getExpirationString();

}

//return a string like ";expires=Thu, 5 Jan 2006 16:07:52 UTC"

function getExpirationString() {

var exp = new Date();

var threemonths = exp.getTime()+(120*24*60*60*1000);

exp.setTime(threemonths);

return ";expires="+exp.toGMTString();

}

This is called from the event handler in the HTML.

<input name="myTextBox" type="text" id="myTextBox"

onchange="javascript:TextBoxOnchange()" />