How can I send a value (for ex id) from one asp page to another at the click of a button (not submit button)?

really this is not ASP but javascript - to send the item - eg a session id - create a hidden control <input type="hidden" name="h1" value="<%=Session("MySessionVariable")%>"/>
and a button
<input type="button" name="btn1" value="Hit me hard" onclick="iamHit(this)"/>
with some javascript
<script>
function iamHit(ctl)
{
ctl.form.action="next_page.asp"
ctl.form.submit()
}
</script>