Using .append() in a loop to add text from an object after a <select> based on the selected option

I want to insert a peace of text under a dropdown menu after an option has been selected based on what option was selected. I've written code that will do exactly what I want it to. But it seems like there should be a faster and more elegant way to handle what I'm trying to do. I'm thinking loop but loops confuse me a bit and I'm not sure what I've done wrong with the function I wrote to try do this.

Here is my original working code:

$('#Total_Package_Pool_Size').change(function() {               
    $('#PS_Dyn_warn').empty();
    $('#PS_Dyn_warn').append("This is the exact size of the pool, this is not an up to size.")

    var PS_Warning_Obj = {
        one : " A pool 14 x 28 is track space 14 and track length 29",
        two : " A pool 16 x 32 is track space 16 and track length 33",
        three: " A pool 18 x 34 is track space 18 and track length 35",
        four : " A pool 20 x 40 is track space 20 and track lenght 41"
    };

    var PS_Warning = document.getElementById('PS_Dyn_warn');
    var sizeDD = document.getElementById('Total_Package_Pool_Size');
    var sizeOpt = sizeDD.options[sizeDD.selectedIndex].text;
    switch (sizeOpt) {
        case "14 x 28":
            $('#PS_Dyn_warn').show();
            $("#PS_Dyn_warn").append(PS_Warning_Obj.one);
         break;
        case "16 x 32":
            $('#PS_Dyn_warn').show();
            $("#PS_Dyn_warn").append(PS_Warning_Obj.two);
         break;
        case "18 x 36":
            $('#PS_Dyn_warn').show();
            $("#PS_Dyn_warn").append(PS_Warning_Obj.three);
         break;
        case "20 x 40":
            $('#PS_Dyn_warn').show();
            $("#PS_Dyn_warn").append(PS_Warning_Obj.four);
         break;
    }   
});

And here is the loop I tried to write:

    var PS_Warning_Obj = {};
    PS_Warning_Obj['14x28'] = [" A pool 14 x 28 is track space 14 and track length 29"];
    PS_Warning_Obj['16x32'] = [" A pool 16 x 32 is track space 16 and track length 33"];
    PS_Warning_Obj['18x36'] = [" A pool 18 x 34 is track space 18 and track length 35"];
    PS_Warning_Obj['20x40'] = [" A pool 20 x 40 is track space 20 and track lenght 41"];
function Dynamic_PS_Warning() {
        $('#PS_Dyn_warn').empty();
        $('#PS_Dyn_warn').append("This is the exact size of the pool, this is not an up to size.")
        var sizeDD = document.getElementById('Total_Package_Pool_Size');
        var sizeOpt = sizeDD.options[sizeDD.selectedIndex].text;
        var PS_Warning = document.getElementById('PS_Dyn_warn');

        var psArray = PS_Warning_Obj[sizeOpt];
        if (psArray) {
            for (var i = 0; i < psArray.length; i++) {
                for (x in PS_Warning_Obj) {
                    if (psArray === sizeOpt) {
                        PS_Warning.append(PS_Warning_Obj[x];
                    }
                }
            }
        }
    }