node command does not work with host name

     when HTTP_REQUEST {  
        set uri [HTTP::uri]
        set host [URI::host $uri]
        set port [URI::port $uri]
        set query [URI::query $uri]
        set basename [URI::basename $uri]

        if {[string bytelength $query] > 0} {  
            set query [format "?%s" $query]
        }  
        if {[string bytelength $basename] > 0} {  
            set truncated [format "%s%s%s" [URI::path $uri] $basename $query ]
        }  else {  
            set truncated [format "%s%s" [URI::path $uri] $query]
        }  
        if {[scan $host "%d.%d.%d.%d" a b c d] != 4} {  
            HTTP::uri $truncated
            NAME::lookup $host
            HTTP::collect
        } else {  
            use node $host 80
        }  
     }  

     when NAME_RESOLVED {  
        set address [NAME::response address 0]
        use node $address 80
        HTTP::release
     }