store data and send email when condition is met

I have a form that when submitted uses php to store the information in
a table, but I also need it to send an email when a condition is met

<select name="safe_access">
<option value="0"></option>
<option value="yes">Yes</option>
<option value="no">No</option>
</select>

if someone selects no as an option in the above drop box how do I get
it to also send an email while still storing the data

thanks