filefield image compability

i have a node type with filefield image cck field
field have required dimensions of image (640x480)
if i choose image smaller and try to add it i have this error in js console:

Uncaught exception: TypeError: '$(notice).purr' is not a function
Error thrown at line 11, column 0 in <anonymous function: Drupal.behaviors.purr_messages>(context) in http://xxxxx/node/add/mytype:
    $(notice).purr();
called from line 41, column 6 in <anonymous function: Drupal.attachBehaviors>() in http://xxxx/misc/drupal.js?3:
    this(context);
called via Function.prototype.call() from line 12, column 15609 in <anonymous function: each>(G, K, F) in http://xxxx/sites/all/modules/jquery_update/replace/jquery.min.js?3:
    if(K.call(G[E],E,G[E])===false)
called from line 40, column 4 in <anonymous function: Drupal.attachBehaviors>(context) in http://xxxx/misc/drupal.js?3:
    jQuery.each(Drupal.behaviors, function() {
called from line 196, column 4 in <anonymous function: Drupal.ahah.prototype.success>(response, status) in http://xxxxx/sites/all/modules/jquery_update/replace/ahah.js?3:
    Drupal.attachBehaviors(new_content);
called from line 85, column 6 in <anonymous function: success>(response, status) in http://xxxxx/sites/all/modules/jquery_update/replace/ahah.js?3:
    return ahah.success(response, status);
called from line 20, column 815 in <anonymous function: a.success>(r, s, A) in http://xxxxxx/sites/all/modules/jquery_update/replace/jquery.form.js?3:
    k[j].apply(a,[r,s,A||h,h])
called from line 14, column 400 in s() in http://xxxxx/sites/all/modules/jquery_update/replace/jquery.form.js?3:
    g.success(n,"success");
called from line 1, column 0 in <anonymous function>(event) in http://xxxxx/node/add/mytype:
    (jQuery(this).data('form-plugin-onload'))()
called from unknown location in program code:
    /* no source available */

without this module i was able to see message that attached image is smaller than required.