The following program multiplies two numbers, the program quits when
one of the number is zero.


BEGIN{print "Enter the Numbers to be multiplied separated by spaces";multply()}
function multply()
{
 getline
 oper1=$1
 oper2=$2
 print (oper1*oper2)
 if (oper1=="0"||oper2=="0") exit
 else
   multply()
}
END{}