javascript - Understanding this go back logic -

javascript - Understanding this go back logic -

i saw go code in website , trying utilize on website. having problem in understanding how tourl , refurl beingness generated in it. please guide structure. thanks

var backtriggered = false; settimeout('goback()',timer); function goback() { if(backtriggered) homecoming false; backtriggered = true; tourl=getwelcomecookie('tourl'); refurl = getwelcomecookie('refurl'); var reg = /(.*)\/sites\/(.*)\/(\d{4})\/(\d{2})\/(\d{2})\/(.*)\/?/; if(reg.test(tourl) == false){ document.cookie="tourl"+ "=" +escape(tourl)+";path=/; domain=.mycsnippets.com; expires=thu, 01-jan-1900 00:00:01 gmt"; document.cookie="refurl"+ "=" +escape(tourl)+";path=/; domain=.mycsnippets.com; expires=thu, 01-jan-1900 00:00:01 gmt"; } location.href=tourl; }

document.cookie="tourl"+ "=" +escape(tourl)+";path=/; domain=.mycsnippets.com; expires=thu, 01-jan-1900 00:00:01 gmt";

this line puts value in brower's cookie store. more info think should read first: http://en.wikipedia.org/wiki/http_cookie

javascript logic