I probably could do a little better if your question was a little more detailed, but...

print "What's the limit?: "
chomp($limit = <STDIN>);

foreach (1 .. $limit) {
    print "enter variable $_ : ";
    chomp($somehash{$_} = <STDIN>);
}
[download]

If this doesn't do it for ya, I'll try again ;)

Looking at BlaisePascal's post, it kinda does look like a homework assignment, but I'll be nice and leave this here anyway.