Try:
if [ -e /path/to/file ] ; then
.....
else
.....
fi

Also, with awk, when you define an external variable to an internal one, make sure the external is set... In clearer terms, see the following:

grep $1 $FILE | awk -F, -v ARG2=$2 '{print $1 $ARG2}'
(Example from one of my simple automation scripts at work, where $1 and $2 are the normal shell-assigned arguments.)

In this particular script, called grab, it is called like so:

./grab /*unique identifier*/ /*field number from flat file*/
i.e.- ./grab 015901492 43

That line looks for the unique identifier, then prints out the field number from the comma-delimited (that's what the "-F," is for) flat file I asked for, in the example, 43.

This might not make any sense, but I do hope it helps...