WMIC in Batch File

Can anyone tell me what is wrong with this script?  I have used this exact script with other WMIC commands and it works fine.  The WMIC commands also work fine outside of the script.

FOR /F "tokens=*" %%A in ('wmic DESKTOPMONITOR get ScreenHeight') do SET MyScreenHeight=%%A

FOR /F "tokens=*" %%B in ('wmic DESKTOPMONITOR get ScreenWidth') do SET MyScreenWidth=%%B



REM Removes spaces including trailing spaces from variables

set MyScreenHeight=%MyScreenHeight: =%

set MyScreenWidth=%MyScreenWidth: =%



echo.

echo Your resolution is %MyScreenWidth% x %MyScreenHeight%

pause