Multiple conditions inside if statement

I was trying to write multiple conditions inside the if statement but its not working.

export VAR_NM=abc.txt
export CURR_DT=20131011
export PREV_DT=20131012

if [ ! -z "$VAR_NM" ] && [ $CURR_DT -ne $PREV_DT ]
then
  echo "Yes"
else 
  echo "NO"
fi

It should return Yes but returning NO always.Appreciate any help.

It returns "yes" for me. What OS and Shell are you using?

$ ./testScript
Yes

i did a small correction.sorry abt the last post

Thanks ..confusion solved

No problem. "Yes" is still the correct answer, so it works!