How to Send warning message to user

Hai..I have one question in unix Shell script.Following is the script

System Configuration: lcpu=4 mem=8192MB
kthr memory page faults cpu
----- ----------- ------------------------ ------------ -----------
r b avm fre re pi po fr sr cy in sy cs us sy id wa
2 1 1537569 5572 0 0 1 27 167 0 581 28847 424 6 1 92 1

In the above script ,Field po value greaterthan 9 How to send a waring message to the user.

One more question.By using cut Command i retrieve one value.How could i assign the value to new variable...

Is anyone facing same kind of problem,plz let me know on this regards

Thanks

P.S.Selvan

I assume that the values are in 5th row always

val=$(sed -n '5p' filename | cut -d " " -f 7)

if [ $val -gt 9 ]
then
wall "po value is greater than 9"
fi