Hello all,
I've been using webdeveloper.com for a while now but I never needed to ask my own question since I usually found it in search, but this time its different

Here is my problem,

I am currently building a page that uses five separate drop down menus (static content) that when selected the combination of what is selected will filter my mysql query and display the correct results using those parameters.

I have everything set up to work when one or another variable is sent, however I am having trouble creating a way to set up the query string where non of the filter options are required.

here is the code that I have so far.

This is my menu code, this will always be static.
HTML Code:
<form name="campsite_search" action="page.html" method="get">
    <select name="state" class="input">
        <option value="all">Select a State</option>
        <option value="MD">Maryland</option>
        <option value="VA">Virginia</option>
        <option value="WV">West Virginia</option>                                                    
        <option value="PA">Pennsylvania</option>
        <option value="DC">Washington D.C.</option>
    <select name="radius" class="input">
    	<option value="all">Radius from Council</option>
        <option value="25">25 miles</option>
        <option value="50">50 miles</option>
        <option value="100">100 miles</option>
        <option value="250">250 miles</option>
        <option value="500">500 miles</option>    
    <select name="size" class="input">
        <option value="all">Please select Camp Size</option>
        <option value="25">25 Campers</option>
        <option value="50">50 Campers</option>
        <option value="100">100 Campers</option>
        <option value="250">250 Campers</option>
        <option value="500">500 Campers</option>
    <select name="type" class="input">
	    <option value="all">Structure type</option>
	    <option value="tent">Tents</option>
	    <option value="cabin">Cabins</option>    
    <select name="activity" class="input">
    	<option value="all">High Adventure Activities</option>
        <option value="0">No</option>
        <option value="1">Yes</option>
<input type="submit" name="submit" class="input" value="Continue" />
and here is my php code that deals with the query, it is far from finished, not even using all the options in the drop down. I started trying to build a big if/elseif tree but that isn't working out. I am also using the smarty and pear libraries, so I apologize if it looks non-standard.

PHP Code:
              if(isset($_GET['state'])){$state addslashes($_GET['state']);}
$radius addslashes($_GET['radius']);
$size addslashes($_GET['size']);
//dealing with the single filter options
if(($state 'all')&&($radius 'all')&&($size 'all')){
$filter ='';
$state != 'all')&&($radius 'all')&&($size 'all')){                  
$filter "state ='".$state."' ";
$state 'all')&&($radius != 'all')&&($size 'all')){                  
$filter "radius <='".$radius."' ";              
$state 'all')&&($radius 'all')&&($size != 'all')){
$filter "camp_size <='".$size."' ";
$order "camp_size ASC";

$rs $a->select($view,$filter,$order,$offset,$limit); 
what I need help with is a way to craft the filtering string so that the options are not required, a catch all way to select any combination of filters and for the query to work.

Any help would be appreciated, and Thank you very much for your time.