There are still store owners who care about customers surfing with Internet Explorer (IE) 6. Recently I was working on IE6 compatibility issues and found the problem which was easy to fix. "Update Shopping Cart" button on shopping cart page doesn't work in IE6. To fix that issue open app\design\frontend\[yourpackage]\[yourtheme]\template\checkout\cart.phtml
Find:
<form action="<?php echo $this->getUrl('checkout/cart/updatePost') ?>" method="post">Change it to:
<form name="update_form" action="<?php echo $this->getUrl('checkout/cart/updatePost') ?>" method="post">Find:
<button type="submit" title="<?php echo $this->__('Update Shopping Cart') ?>" class="button btn-update"><span><span><?php echo $this->__('Update Shopping Cart') ?></span></span></button>Change it to:
<button onclick="document.getElementById('update_form').submit();" type="submit" title="<?php echo $this->__('Update Shopping Cart') ?>" class="button btn-update"><span><span><?php echo $this->__('Update Shopping Cart') ?></span></span></button>Now the update cart button works in IE6.