[help] tool fetch

RouterOS Scripting
1

i’m trying a script to disable some ethernet using this code

:local result [/tool fetch http-method=post port=80 keep-result=no url="xxxxxxxxxxxxxxxx"];
:if ($result->"status" = "finished") do={
            /interface ethernet set ether4 disabled=no;
        } else={
            /interface ethernet set ether4 disabled=yes;
        }

but it wont work , it just disable the ether4, which is i want to disable the ether4 if download failed.
so i just try check the command in terminal

/tool fetch http-method=post port=80 keep-result=no url="xxxxxxxxxxxxxxxx"

its only showing the log

sep/14 05:57:47 info fetch: file “post” downloaded

how to get those “downloaded” result as an variable to get the script works ?