[plt-scheme] Conditions in web-templates

Hi,
I'm using plt web-server for my project.
Content is rendered using web-server/templates module.
I've got a questions about @-syntax:
Is it possible to render a particular template branch using
some condition as a criterion?
I.e. I'd like to be able to write something of the kind:

@if(expr){
	branch1
}
{
	else-branch
}

Thanks.

-- 
~syhpoon