Netwatch Email not showing downtime.

In the netwatch I am getting the correct uptime in my email. But I am not getting the downtime.
What I am doing wrong?
Kindly help to solve the issue.

This is my up script:

:global my
:log error "WAN link is up again"
/tool e-mail send to="xzt@gmail.com" subject="WAN STATUS" body=" WAN Link is up on $[/system clock get time]. Down from $my"

This is my down script:

:global my
:set my  "$[/system clock get time]"
:log error "WAN link is down"

If you meant that email for Downtime has not been sent, it is because you are missing line for sending email in downtime script

No i mean the Downtime is not showing in the up mail. You can see that I used a variable to save the downtime. And that variable is not giving the value.