/* check for aol_promotional_link or aol_cookie (i.e. [partner_site="aol"])
	if either exist, ignore backto functions below, removing "Discovery.com Home" link in tophat 
*/

var kname = "partner_site"
var kval = "aol"
//var expireYear = 2003
//var expireMonth = 5
//var expireDay = 14
//var killDate = new Date(expireYear,expireMonth-1,expireDay).toGMTString()

var std = true;

function getKookie(name) {
	var dcomK = document.cookie
	var nloc = dcomK.indexOf(name)
	if (nloc != -1) {
		var valStart = nloc + (name.length+1)
		var valEnd = dcomK.substring(";",valStart) 
		if (valEnd == -1) valEnd = dcomK.length
		var value = dcomK.substring(valStart,valEnd)
		value = unescape(value)
		return value
	} else return false
}

function setKookie(name,val,exp) {
	var kookie = name+"="+escape(val) +
		"; domain=.discovery.com; path=/;"
	if (exp) kookie += " expires="+exp
	document.cookie = kookie
}

if ( getKookie(kname) == kval ) std = false
else {

	var promo_id = location.hostname.toLowerCase()
	if ( promo_id.indexOf(kval) != -1 ) {
		//setKookie(kname,kval,killDate)
		setKookie(kname,kval)
		std = false;
		} 
	}

if (std) {

	/* backto.js - Conditionally outputs a different top hat image depending on whether MSN referred user to this page */
	msnrefer=".msn.com";
	rf=escape(document.referrer)+"";
	rf=rf.toLowerCase();

	/* Check for URL encoding of http:// */ 
	if (rf.indexOf("http%3a//") == 0) { var rftrunc = rf.slice(9) } 
	else { var rftrunc = rf; }

	/* if referred from MSN */ 
	if ( rf.indexOf(msnrefer) != -1 ) { document.write('<div class="msnBack"><a href="http://'+rftrunc+'" target="_top"  class="black">&#60; BACK TO MSN</a></div>'); }

	/* if not reffered from MSN */ 
	else { document.write('<div class="msnBack"><a href="http://www.discovery.com" target="_top" class="black">DISCOVERY.COM HOME</a></div>'); }

}