i'm using login box v1.4 and would like to add a buttton where it is written login. Should I in the tpl_login_box.php located in the template/template default/sidebox it has this:

$content .='<div class="centeredContent">'.zen_image_submit(BUTTON_IMAGE_LOGIN, BUTTON_LOGIN_ALT).'</div>';
Is this where i would put :zen/images/attributes/a_bugs_life_green.gif
instead of:BUTTON_IMAGE_LOGIN or change it somewhere else?
thank you