follow us icons problem

Dear Titanic developer ,
Thanks for your help again. many appreicate for your support . i have one problem on follow us ” social icons”
“dribbble” & ” “youtube” can’t show icon which i make for myself,not use social icons.png
if i change class=”dribble” to class=”facebook”.it can show facebook icon normally .
please help me again.

refer :
<div class=”socialicons”>
 <span></span> <span></span><span></span><span></span>

Best regards,
loyal