Thickbox doesn’t respect dimensions when used in admin [duplicate]

by 

    <?php
    function wpse_1234() {
    add_thickbox();
    }
    add_action('init','wpse_1234');

    ?>
<a href="#TB_inline?height=300&amp;width=400&amp;inlineId=preview" class="thickbox">View all<a>";
 <div id='preview' style="display:none;"></div>

Try this way it should work for thickbox.you can call those thickbox in a init hook.

Thanks.