var Custom_localStorage={
	//添加缓存时间：7天	
	set:function(key,value,days){	
	    var item={			
	        data:value,			
	        endTime:new Date().getTime()+days*24*3600*1000		
	    }		
	    localStorage.setItem(key,JSON.stringify(item));	
	},	
	get:function(key){		
	    var val=localStorage.getItem(key);		
	    if(!val){			
	        return null;		
	    }		
	    val=JSON.parse(val);		
	    if(new Date().getTime()>val.endTime){		
	    	val=null;			
	    	localStorage.removeItem(key);		
	    }		
	    return val.data;	
	},	
	remove:function(key){		
	    localStorage.removeItem(key);		
	    return null;	
	},	
	removeAll:function(){		
	    localStorage.clear();		
	    return null;	
	}
};