页面写入与读取Cookie

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())
}