$(document).ready(function(){

$(".btn4").hover(
function() {
$("img.a").animate({"opacity": "1"}, "fast");
$("img.b").animate({"opacity": "0"}, "fast");
$("img.c").animate({"opacity": "0"}, "fast");
$("img.d").animate({"opacity": "0"}, "fast");
$("img.e").animate({"opacity": "0"}, "fast");
$("img.f").animate({"opacity": "0"}, "fast");
},
function() {
$("img.a").animate({"opacity": "1"}, "fast");
});
 
$(".btn1").hover(
function() {
$("img.b").animate({"opacity": "1"}, "fast");
$("img.a").animate({"opacity": "0"}, "fast");
$("img.c").animate({"opacity": "0"}, "fast");
$("img.d").animate({"opacity": "0"}, "fast");
$("img.e").animate({"opacity": "0"}, "fast");
$("img.f").animate({"opacity": "0"}, "fast");
},
function() {
$("img.b").animate({"opacity": "1"}, "fast");
});

$(".btn3").hover(
function() {
$("img.c").animate({"opacity": "1"}, "fast");
$("img.a").animate({"opacity": "0"}, "fast");
$("img.b").animate({"opacity": "0"}, "fast");
$("img.d").animate({"opacity": "0"}, "fast");
$("img.e").animate({"opacity": "0"}, "fast");
$("img.f").animate({"opacity": "0"}, "fast");
},
function() {
$("img.c").animate({"opacity": "1"}, "fast");
});

$(".btn2").hover(
function() {
$("img.d").animate({"opacity": "1"}, "fast");
$("img.a").animate({"opacity": "0"}, "fast");
$("img.b").animate({"opacity": "0"}, "fast");
$("img.c").animate({"opacity": "0"}, "fast");
$("img.e").animate({"opacity": "0"}, "fast");
$("img.f").animate({"opacity": "0"}, "fast");
},
function() {
$("img.d").animate({"opacity": "1"}, "fast");
});

$(".btn5").hover(
function() {
$("img.e").animate({"opacity": "1"}, "fast");
$("img.a").animate({"opacity": "0"}, "fast");
$("img.b").animate({"opacity": "0"}, "fast");
$("img.c").animate({"opacity": "0"}, "fast");
$("img.d").animate({"opacity": "0"}, "fast");
$("img.f").animate({"opacity": "0"}, "fast");
},
function() {
$("img.e").animate({"opacity": "1"}, "fast");
});

$(".btn6").hover(
function() {
$("img.f").animate({"opacity": "1"}, "fast");
$("img.a").animate({"opacity": "0"}, "fast");
$("img.b").animate({"opacity": "0"}, "fast");
$("img.c").animate({"opacity": "0"}, "fast");
$("img.d").animate({"opacity": "0"}, "fast");
$("img.e").animate({"opacity": "0"}, "fast");
},
function() {
$("img.f").animate({"opacity": "1"}, "fast");
});

});