F# Async Workflow

#light
open System.IO
open System.Net
open System

let AyncHttp(url:string) =
    async {
        let req=WebRequest.Create(url)
        let! rsp=req.AsyncGetResponse()
        use s= rsp.GetResponseStream()
        use r= new System.IO.StreamReader(s)
       r.ReadToEnd()
    }

//let SyncHttp(url:string) =
//    let req=WebRequest.Create(url)
//    let rsp=req.GetResponse()
//    use s= rsp.GetResponseStream()
//    use r= new System.IO.StreamReader(s)
//    r.ReadToEnd()



let dt=System.DateTime.Now

//SyncHttp "http://maps.google.com"
//SyncHttp "http://maps.live.com"
//SyncHttp("http://www.nhl.com");
//SyncHttp("http://www.nfl.com");
//SyncHttp("http://www.china.com");
//SyncHttp("http://www.sina.com");
//SyncHttp("http://www.nba.com");
//printf "%A" (DateTime.Now-dt).Milliseconds

Async.Parallel [ 
    AyncHttp("http://maps.google.com"); 
    AyncHttp("http://maps.live.com");
    AyncHttp("http://www.nhl.com");
    AyncHttp("http://www.nfl.com");
    AyncHttp("http://www.china.com");
    AyncHttp("http://www.sina.com");
    AyncHttp("http://www.nba.com");
    ]
    |> Async.RunSynchronously

printf "%A" (DateTime.Now-dt).Milliseconds