button onclick function firing twice

Maybe you are attaching the event twice on the same button. What you could do is unbind any previously set click events like this:

$('.addToCartButton').unbind('click').click(function() {
    alert("bob");
    //addToCart($(this).attr("id"));
});

This works for all attached events (mouseover, mouseout, click, ...)

My event was firing twice because I accidentally included both my_scripts.js AND my_scripts.min.js. Ensure you only include one.

Unbind event from selector and after appending in element in DOM again trigger event on specific selector.. $("selector_name").unbind( "event" ); //After this call event on selector again..

For example:

$( "#button" ).unbind( "click" );

$("#button").click(function(event) {
console.log("button click again);
});