PHP if语句与html结合[关闭]

It's possible to combine a php if statement if i have for example this code:

<div id="contentArea">classic content field</div>

This id is html, and my question is, can i do a if statement with php if my html id is not empty...

for example so:

if(!empty('MY_HTML_ID')) { echo '<div id="contentArea"></div>'; }

Why PHP? You should use something like that (jquery example):

if( $('#MY_HTML_ID').is(':empty') ) { }

or:

if( $('#MY_HTML_ID:empty').length ) { }

Edit: If you are using a template system, you can also check the variable inside of the div, for example with this logic:

<div>
    <% if $MyDinner %>
        You can do the request
    <% else %>
        You can't, because the variable $MyDinner has no value
    <% end_if %>
</div>