Help in selecting line numbers between two values

Hi! I've a file as shown below

1 hello
2 how
5 are
3 you
4 hello
5 world

Every statement consists of line numbers at the beginning which are not in sequence.

Now I want to select all the line numbers which are present between the line numbers specified by the user..

For example if the user gives the following input,
starting line number START=2
and ending line number END=4

Then I want all the line numbers which are in between 2 and 4(including START and END) in the given program..
The output has to as shown below

2
5
3
4

How can I accomplish this??
Thanks in advance..

$ cat tst
1 hello
2 how
5 are
3 you
4 hello
5 world
$ START=2
$ END=4
$ awk -v s="$START" -v e="$END" '$1==s{f=1}$1==e{print;f=0}f' tst
2 how
5 are
3 you
4 hello
$

---------- Post updated at 12:57 AM ---------- Previous update was at 12:55 AM ----------

If you only need the first column

$ awk -v s="$START" -v e="$END" '$1==s{f=1}$1==e{print $1;f=0}f{print$1}' tst
2
5
3
4