Try:
$("#"+styleTarget).css({ 'font-size': $(this).val() });
By putting the value in quotes, it becomes a string, and "+$(this).val()+"px
is definitely not close to a font value. There are a couple of ways of setting the style properties of an element:
Using a map:
$("#elem").css({
fontSize: 20
});
Using key and value parameters:
All of these are valid.
$("#elem").css("fontSize", 20);
$("#elem").css("fontSize", "20px");
$("#elem").css("font-size", "20");
$("#elem").css("font-size", "20px");
You can replace "fontSize"
with "font-size"
but it will have to be quoted then.