Check for request.GET variable in the template

Variables are case-sensitive - so, assuming as lazerscience points out that you actually have the request object in the context, you would need to use {% if request.GET.my_var %}.

Check if you have django.core.context_processors.request in your TEMPLATE_CONTEXT_PROCESSORS in settings.py.

If not put it there, or add request yourself to your rendered context.

http://docs.djangoproject.com/en/dev/ref/templates/api/#django-core-context-processors-request