BASH and NMAP

[DeadBeet]

[root@pxe tmp]# vi test1
#!/bin/bash

a="nmap -p80 xx.xx.xx.xx | awk '{print $2}'|grep open"
b="open"

echo

if [ "$a" != "$b" ]
then
echo "doesn't match"
elif
["$a" == "$b" ]
then
echo "Matches!"
fi

It always comes back as "doesn't match". I also get this error when I have the variable set in the environment:

[root@pxe tmp]# a="nmap -p80 xx.xx.xx.xx| awk '{print $2}'|grep open"
[root@pxe tmp]# $a

Starting Nmap 4.11 ( http://www.insecure.org/nmap/ ) at 2011-07-11 10:11 MST
Invalid target host specification: |
QUITTING!

I'm thinking this error would be the issue. What am I doing wrong?

Please note, the xx.xx.xx.xx is actually an IP address in my script

[DeadBeet]

Fixed, here's the revised script:

#!/bin/bash

a=$(nmap -p80 xx.xx.xx.xx | awk '{print $2}'|grep open)
b="open"

eval "$a"
echo

if [ "$a" != "$b" ]
then
service httpd start
fi