js设置，获取cookie

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