function setCookie(cname,cvalue,chours) {
 if (chours) {
 var date = new Date();
 date.setTime(date.getTime()+(chours*60*60*1000));
 var expires = "; expires="+date.toGMTString();
 }
 else var expires = "";
 document.cookie = cname+"="+cvalue+expires+"; path=/";
}
function readCookie(cname) {
 var nameEQ = cname + "=";
 var ca = document.cookie.split(';');
 for(var i=0;i < ca.length;i++) {
 var c = ca[i];
 while (c.charAt(0)==' ') c = c.substring(1,c.length);
 if (c.indexOf(nameEQ) == 0) return c.substring(nameEQ.length,c.length);
 }
 return null;
}
function eraseCookie(cname) {
 __SetCookie(cname,"",-1);
}