{assign var="_DefaultLoginTemplate" value=vtemplate_path('Login.Default.tpl', 'Users')}
{assign var="_CustomLoginTemplate" value=vtemplate_path('Login.Custom.tpl', 'Users')}
{assign var="_CustomLoginTemplateFullPath" value="layouts/slayout/$_CustomLoginTemplate"}

{if file_exists($_CustomLoginTemplateFullPath)}
        {include file=$_CustomLoginTemplate}
{else}
        {include file=$_DefaultLoginTemplate}
{/if}