array in query string

1.aspx

ArrayList arr = new ArrayList();
arr.Add("file1″);
arr.Add("file2″);
arr.Add("file3″);
string arry = String.Join(",", ((string[])arr.ToArray(typeof(String))));
Response.Redirect("1.aspx?file=" + arry);

2.aspx

string[] files = Request["file"].ToString().Split(‘,’);
ArrayList arry = new ArrayList();
foreach (string file in files)
{
arry.Add(file);
}

1.aspx

ArrayList arr = new ArrayList();
arr.Insert(0, "file1″);
arr.Insert(1, "file2″);
arr.Insert(2, "file3″);
Cache["test"] = arr;
arr = null;
Response.Redirect("2.aspx");

2.aspx

ArrayList ary = new ArrayList();
ary.Add(Cache["test"]);
Cache.Remove("test");