How to get the selected option value of a drop down box in PHP code

Answer 1

if you can put the src of image in value of you select option or put attribute of image in hidden div to the value of the item you are showing in select option it will be really easy. Like:

CASE 1) Putting img src in value property of option

....

$("#logoMenu").change(function(){
    var logo=$("#logoMenu option:selected").attr("value");
    $("#theme_logos img").hide();
    $("#theme_logos img[src='"+logo+"']").show();
})

CASE 2) Putting image's alt to value in option

..

$("#logoMenu").change(function(){
    var alt=$("#logoMenu option:selected").attr("value");
    $("#theme_logos img").hide();//hide any other logo that is showing
    $("#theme_logos img[alt='"+alt+"']").show();//show selected logo
})

EDIT:- Test Code (CASE 2)