Hello,
I can't manage to finish this challenge. I got this error : 
" The 'ShowAssistantInfo' page isn't referencing the Assistant Name variable."
I used the <apex:variable> to create the variables but still got the error.

Here is my code :

<apex:page docType="html-5.0" standardController="Contact" title="Assistant Information">
    <apex:variable var="AssistantName" value="{!Contact.Name}" />
    <apex:variable var="AssistantPhone" value="{!Contact.Phone}" />
	<p>Assistant : {!AssistantName}</p>
	<p>Phone : <a href="tel:{!AssistantPhone}">{!AssistantPhone}</a></p>
</apex:page>

Thanks