{% load thumbnail %}

{% spaceless %}

<a href="{{ sponsor.external_url }}">

    {% if dimensions %}

        <img id="sponsor_{{ sponsor.pk }}" src="{% thumbnail sponsor.logo dimensions %}" alt="{{ sponsor.name }}" />

    {% else %}

        <img id="sponsor_{{ sponsor.pk }}" src="{% thumbnail sponsor.logo '150x150' %}" alt="{{ sponsor.name }}" />

    {% endif %}

</a>

{% endspaceless %}