I have
<option> A </option>
<option> B </option>
.... till F

<script>
then user enters number, (must validate)
(assuming he chose A),
then if (A>10 && A < 25)
A is true
else it's false

but if he chooses B, then different range...
</script>

anyone can write this? I tried but it didn't work. wanted to paste the program here but it was too big...