onLoad=checkCookie()

function getCookie(c_name)
{
if (document.cookie.length>0)
{ 
c_start=document.cookie.indexOf(c_name + "=")
if (c_start!=-1)
{ 
c_start=c_start + c_name.length+1 
c_end=document.cookie.indexOf(";",c_start)
if (c_end==-1) c_end=document.cookie.length
return unescape(document.cookie.substring(c_start,c_end))
} 
}
return ""
}

function setCookie(c_name,value,expiredays)
{
var exdate=new Date()
exdate.setDate(exdate.getDate()+expiredays)
document.cookie=c_name+ "=" +escape(value)+
((expiredays==null) ? "" : "; expires="+exdate.toGMTString())
}

function checkCookie()
{
username=getCookie('username')
if (username!=null && username!="")
 {alert('Welcome Back '+username+'!') 
document.write('Login: '+username+'<br/>Welcome back to my site')}
else 
  {
 username=prompt('masukan nama kamu:',"") 
document.write('welcome.... <u>'+username+'</u><br/>stay with my site and please Bookmark this page!')

  if (username!=null && username!="")
    {
    setCookie('username',username,365)
    }
  }
}