1)
the map with the web page address and different requestid as the parameter.
2)
in that page, use php if elseif or switch case to see what list you will show
such as if requestid 2222613 is for illinois
and 222614 is for wisconsin
<?php
if ($requestid=="2222613")
{ ?>
<select name="city">
<option value="Chicago">Chicago</option>
<option value="Spring Field">Spring Field</option>
</select>
<?php
}
elseif ($requestid=="2222614")
{
?>
<select name="city">
<option value="Milwaukee">Milwaukee</option>
<option value="Madison">Madison</option>
</select>
<?php
}
elseif (..)
{
?>
....
