找某字符串的所有非空字串

//题目：找出www.xx.com所有非空字串
var str = "www.xx.com",
	count = {},
	i = 0;

function cutstr(str,first,len){
	if(first+len <= str.length){
		while(first+len <= str.length){           
			var s = str.substr(first,len);

			first++;
			count[s]=0;
		}
		arguments.callee(str,0,++len);
	}
}

cutstr(str,0,1);
for(var key in count){
	console.log(++i);
	console.log(key);
}

 可惜答题那天算错鸟，悲剧。