Issues with add_query_arg() not passing a variable

I ended up using a GET method and got rid of add_query_arg() function

$homezip = $_GET["search"];
<form action="local-concert-listings/" method="get">
        <input  id="address" size="6" type="text" placeholder="Zipcode" name="zipcode"/>
         <div style="display:none;">
         <input id="volume" size="1" name="miles" value="70" placeholder="70"></input>
              </div>      
         <input type="submit" value="go" name="SubmitButton" onclick="codeAddress()" />
 </form>