The “No Avatar” image if there is no avatar


I’m making a site on DLE, I’ve had problems with avatars. That is, if the user logged in and uploaded an avatar in the profile, then the avatar is displayed in the comments, but if the comment is written on behalf of the guest, then there is no avatar.

Question. How to make it so that if there is no avatar, the picture “No Avatar” is put?

Comments.tpl file code:

<table width="100%" border="0" cellpadding="0" cellspacing="0" class="comment-form">
    <td width="15%" valign="top">
    <div class="foto"><img src="{foto}" /></div>
    <td width="85%" valign="top">
    <div class="gr-date"><p style="float:left;">:<span style="color:#F00;">{group-name}</span></p><p style="float:right;">{date}</p></div>
    <br style="clear:both;" />
    <br style="clear:both;" />
    <div class="edit">
    [group=1,2][com-edit]<p style="font-size:11px;color:gray; text-decoration:underline; float:left;"></p>[/com-edit]
    [com-del]<p style="font-size:11px;color:gray; text-decoration:underline; float:right; margin-left:25px;"></p>[/com-del][/group]
    [group=1,2,3][fast]<p style="font-size:11px;color:gray; text-decoration:underline; float:right; margin-left:25px;"></p>[/fast][/group]</div>

Answer 1, authority 100%

You go to the folder with the template, in the images folder you throw a picture with the name noavatar.png