I need to see if I can shorten this AND see if I can have a "show all option" added.

The page is setup like so..
I have the following javascript working.. I'm running jquery... being a semi newbie it took a while to get this running.

I have 4 DISTINCT queries that load up select boxes.

There are 4 select boxes .. on change, the queries will see what option was selected and re-run DISTINCT SQL queries so all the select boxes only have related info.. so no one ends up with a "zero" results.

I'm hiding these to help walk through in a logical order. However I need to
1) Have a show all and let them select anything they wish and show all 4 boxes. How can I add a "show all" to the script below
2) I noticed on page load the boxes show and then slowly hide. THis looks messy.. how can I alter that?
3) This seems long for what I'm doing.. is there a way I can shorten this code? What if I expand to 8 boxes.. then I'll have 8 simple if statements.. but it seems unnecessary.

CODE that is working is


$(document).ready(function () {
if ($("#pMaterial option").is(":selected"))
{
//show the hidden div
$("#pPoint").show("fast");
}
else
{
//otherwise, hide it
$("#pPoint").hide("fast");
}

if ($("#pPoint option").is(":selected"))
{
//show the hidden div
$("#pLength").show("fast");
}
else
{
//otherwise, hide it
$("#pLength").hide("fast");
}
if ($("#pLength option").is(":selected"))
{
//show the hidden div
$("#pThread").show("fast");
}
else
{
//otherwise, hide it
$("#pThread").hide();
}
if ($("#pThread option").is(":selected"))
{
//show the hidden div
$("#pDiameter").show("fast");
}
else
{
//otherwise, hide it
$("#pDiameter").hide();
}
if ($("#pDiameter option").is(":selected"))
{
//show the hidden div
$("#pFinish").show("fast");
}
else
{
//otherwise, hide it
$("#pFinish").hide();
}
});

The boxes are wrapped in divs like so
<div id="pMaterial" style="width:150px;float:left;">select box here</div>
<div id="pPoint" style="width:150px;float:left;">select box here</div>

Any help is greatly appreciated