function num_check()
{
	read -p "$1" as
	until expr $as - 1 >>/dev/null 2>/dev/null 
	do
		read -p "$2 should be numeric please enter again" as
	done
	echo $as
}
function char_check()
{
read -p "$1" as
while expr $as - 1 >>/dev/null 2>/dev/null 
do
read -p "$2 should not be numeric please enter again" as
done
echo $as
}
function null_check()
{
read -p "$1" as
while [ -z $as ]
do
read -p "$2 should not be null " as
done
echo $as
}
function alphacheck()
{
read -p "$1" as
while echo $as | grep [0-9\!\@\#$\%\^\&\*\(\)\-\_\|] 2>>/dev/null >>/dev/null
do
read -p "$2 should be alphabet only" as
done
echo $as
}
#
#	sample calling for the script
#
#
#z=`num_check "Please enter the no" "Customer no" `
#echo $z
#echo `expr $z + 1`
#y=`char_check "Please enter the name" "Customer name"`
#echo $y
#echo $y | wc -c
#x=`null_check "Please enter enrollment no" "enrollment no"`
#q=`alphacheck "Please enter the name" "Customer name"`
#echo $q