Custom metabox for multiple images gives a JQuery error saying a function does nog exist

I have a script that creates a custom metabox and makes it possible to upload multiple images to one page post.

It gives me no error but the console tells me this:

TypeError: add_field_row is not a function

This is the JQuery:

<script type="text/javascript">
    function add_image(obj) {
        var parent=jQuery(obj).parent().parent('div.field_row');
        var inputField = jQuery(parent).find("input.meta_image_url");

        tb_show('', 'media-upload.php?TB_iframe=true');

        window.send_to_editor = function(html) {
            var url = jQuery(html).find('img').attr('src');
            inputField.val(url);
            jQuery(parent)
            .find("div.image_wrap")
            .html('<img src="'+url+'" height="48" width="48" />');

            // inputField.closest('p').prev('.awdMetaImage').html('<img height=120 width=120 src="'+url+'"/><p>URL: '+ url + '</p>'); 

            tb_remove();
        };

        return false;  
    }

    function remove_field(obj) {
        var parent=jQuery(obj).parent().parent();
        //console.log(parent)
        parent.remove();
    }

    function add_field_row() {
        var row = jQuery('#master-row').html();
        jQuery(row).appendTo('#field_wrap');
    }
</script>

I don't see where I go wrong. And if I'm not mistaken I don't need to use the ready() because I'm not using a $

jQuery(document).ready(function($){
// now you can use jQuery code here with normal $ shortcut formatting
}); 

I've tried to be sure but same error.

Any help please.