// Boolean variable specified if alert should be displayed if cookie exceeds 4KB
var caution = false

// name - name of the cookie
// value - value of the cookie
// [expires] - expiration date of the cookie (defaults to end of current session)
// [path] - path for which the cookie is valid (defaults to path of calling document)
// [domain] - domain for which the cookie is valid (defaults to domain of calling document)
// [secure] - Boolean value indicating if the cookie transmission requires a secure transmission
// * an argument defaults when it is assigned null as a placeholder
// * a null placeholder is not required for trailing omitted arguments
function setCookie(name, value, expires, path, domain, secure) {
var curCookie = name + "=" + escape(value) +
((expires) ? "; expires=" + expires.toGMTString() : "") +
((path) ? "; path=" + path : "") +
((domain) ? "; domain=" + domain : "") +
((secure) ? "; secure" : "")
if (!caution || (name + "=" + escape(value)).length <= 4000)
document.cookie = curCookie
else
if (confirm("Cookie exceeds 4KB and will be cut!"))
document.cookie = curCookie
}

// name - name of the desired cookie
// * return string containing value of specified cookie or null if cookie does not exist
function getCookie(name) {
var prefix = name + "="
var cookieStartIndex = document.cookie.indexOf(prefix)
if (cookieStartIndex == -1)
return null
var cookieEndIndex = document.cookie.indexOf(";", cookieStartIndex + prefix.length)
if (cookieEndIndex == -1)
cookieEndIndex = document.cookie.length
return unescape(document.cookie.substring(cookieStartIndex + prefix.length, cookieEndIndex))
}

// name - name of the cookie
// [path] - path of the cookie (must be same as path used to create cookie)
// [domain] - domain of the cookie (must be same as domain used to create cookie)
// * path and domain default if assigned null or omitted if no explicit argument proceeds
function deleteCookie(name, path, domain) {
if (getCookie(name)) {
document.cookie = name + "=" +
((path) ? "; path=" + path : "") +
((domain) ? "; domain=" + domain : "") +
"; expires=Thu, 01-Jan-70 00:00:01 GMT"
}
}

// date - any instance of the Date object
// * you should hand all instances of the Date object to this function for "repairs"
// * this function is taken from Chapter 14, "Time and Date in JavaScript", in "Learn Advanced JavaScript Programming"
function fixDate(date) {
var base = new Date(0)
var skew = base.getTime()
if (skew > 0)
date.setTime(date.getTime() - skew)
}

var now = new Date()
fixDate(now)
now.setTime(now.getTime() + 31 * 24 * 60 * 60 * 1000)
var name = getCookie("name")
if (!name)
name = prompt("Please enter your name:", "John Doe")
setCookie("name", name, now)
document.write("Hello " + name + "!")
//-->
</script>