Making PHP5 default version in Virtualmin

I need to have PHP execution mode run as Apache mod_php with php5. However, the default is php4. When I changed to mod_php using Virtualmin Pro, the php is the default version 4. I have installed Php5 onto my server and can enable for each individual site. However, it looks like I need to have php5 as the default php.

Please advise how this can be achieved?

Thanks