it's really simple.. with .htaccess
hi,
simple create a file named ".htaccess" in the folder where you can to create DirectoryIndex rule.
copy and paste following line in .htaccess file
DirectoryIndex default.html index.html index.cgi index.php
note: everything after DirectoryIndex is priority. ie in above example " default.html " is first priority " index.html" is second.
in your case you just can put below line and it should be fine:
DirectoryIndex index.html index.php
If you are using windows:
1. make sure that your file name is correct " .htaccess " cause windows doesn't allow to create file extension starting with " . " , that is dot
2. quick way is, first create htaccess.txt , do your requirement and finally go to " cmd " > navigate to your folder location and rename file from " htaccess.txt " to " .htaccess "
good luck...