Creating hash with my imput

[rolandomantilla]

I'm trying to write a program that uses a loop to prompt a user to input a key/value pair to then store it in a hash until the user put if exit but i'm kinda lost. This is what I have until now I'm not getting any problems but after the first id/dna it stops

#!/usr/bin/perl

%hash={ };
print ("put ID fallowed by a comma"," with the DNA for that ID\n\n");

$id=<STDIN>;

chomp $id;

@DNA=$id;

foreach( $id){
%hash= (@DNA);
if ($id){ print "Please enter another ID and DNA"}
else {print "Exit";}
 exit;}
print %hash;