I think this will be more robust.......u can test this script for as many files as u want.....

#!/bin/sh
#script to cat number of files given as an argument
if [ $# -eq 0 ]
then
echo " Enter the files which are to be catted as argument "
fi
if [ $# -eq 1 ]
then
echo " usage :: $0 <outputfile> <inputfile1> <inputfile2> ......."
fi
count=`expr $# - 1`
echo $count
echo $*
#shift jam1 > jam2
#cat jam2
#i=2
catfile=$1
while [ $# -gt 1 ]
do
echo $*
cat $2 $3 > jam
shift 2
done
cat jam > catfile

txs,
jam