$(document).ready(function(){
var zipCodes   =[60538,60504,75001,76008,75002,75013,76009,76225,75409,76226,76001,76002,76006,76010,
76011,76012,76013,76014,76015,76016,76017,76018,76227,76020,75413,75180,75101,76021,
76022,75414,76126,75424,75418,76023,76028,75135,75006,75007,75010,76127,75104,75423,
75009,75105,76031,75211,76034,76233,75121,75019,75114,76035,76036,];
$("#buttontest").click(function(){
 var zipIndex = zipCodes.indexOf(parseInt($("#full_day").val()));
 $("#zipMessage > div").hide("fast");
 var zipId = zipIndex > -1 ? zipCodes[zipIndex] : "Error";
$("#zip"+zipId).show("fast");
});

$("#full_day").keydown(function(e){
  if(e.which === 13){
     $("#buttontest").click();
}
});
});

$("#some_button").on('click', function(e) {
    $.ajax({
        type: 'POST',
        url: 'some_php_script.php',
        data: {foo : "bar"}
    })
    .done(function(results) {
        // check to see if results is actually html
        // going to assume it is for the sake of example
         $("#zip60538").html(results);
    });
});