If you only have one image, I suggest you give it an ID instead of (ab)using the classname.
If you have several and use the same image for all, then change $("#myImage") below to $(".img-button")
Toggle
$(document).ready(function(){
$("#myImage").toggle(
function() {
$(this).attr('src','images/pressed.jpg');
},
function() {
$(this).attr('src',"images/default.jpg");
});
});
Swap after leaving
$(document).ready(function(){
$('#myImage').on("click",function() {
$(this).attr('src','images/pressed.jpg');
});
$('#myImage').on("mouseleave",function() {
$(this).attr('src',"images/default.jpg");
});
});
Swap half a sec after pressing
$(document).ready(function(){
$('#myImage').on("click",function() {
$(this).attr('src','images/pressed.jpg');
setTimeout(function() {
$('#myImage').attr('src',"images/default.jpg");
},500);
});
});