common deal with cookies

common deal with cookies.js

// From Flanagan's book
// Recieve all document cookies
var allcookies = document.cookie;
// Search desired cookie
var pos = allcookies.indexOf("version=");
// If founded, extract it and use it's value
if (pos != -1) {
	var start = pos + 8;
	var end = allcookies.indexOf(";". start); // Start of value
	if (end == -1) end = allcookies.length; // End of value
	var value = allcookies.substring(start, end); // Extract it
	value = decodeURIComponent(value); // Decode it
	// Deal with it!
	if (value != document.lastModified)
		alert("Document was modified since your last visit!");
}