Problem displaying power metering variable (blank message)

I have a problem getting Vera Alerts to display a variable. It is for a power meter device,
device_type urn:schemas-micasaverde-com:device:PowerMeter:1
If I put this into test luup code, I can find this as a corresponding line in the Vera log:

luup.log(luup.variable_get(“urn:micasaverde-com:serviceId:EnergyMetering1”, “Watts”, 379) or “undefined”)

10/01/14 15:08:59.480 Device_Variable::m_szValue_set device: 379 service: urn:micasaverde-com:serviceId:EnergyMetering1 variable: Watts was: 667 now: 644 #hooks: 1 upnp: 0 v:0xed08b8/NONE duplicate:0 <0x3248c680>

so I thought this put into Vera Alerts send would work:


but that gives me a blank message. 379 is the device number of my power meter