Add to Bag image - how to change

how do i change the add to bag image on my product page to an image i have already?

any help will be appreciated!

It is referenced in styles.css in your /skins/(skinname)/customer/styles.css

Checkout the image before just uploading a replacement as it contains the 'empty' and 'has items' cart icons…

.cart-icon {
float: left;
display: inline-block;
width: 30px;
height: 15px;
background: url(images/icons/cart_icon.png) 0 0 no-repeat;

Sorry limbomania - I am guilty of not reading your post correctly! Do you mean the 'Add To Cart' button?