after adding $! , am getting the following error in my gi

Software error: Cannot make directory /var/www/html/piRNA_html/UNAFold/output/10010 , errorwas:Permission denied at /var/www/html/piRNA_html/UNAFold/mkdirtest.cgi line 39.

i couldnt understand , though 0777 permission given , y its giving error about permission, please reply me in this