Code error for first post banner

[HeRCuL70]

Admin CP -> Styles & Templates -> Style Manager -> « » -> Postbit Templates -> postbit

<if condition="$post[postcount] % X == 10">
<center>
          BANNER CODE HERE
</center>
</if>

I get tempelate error as below

The following error occurred when attempting to evaluate this template:

Warning: Division by zero in \includes\adminfunctions_template.php(3596) : eval()'d code on line 99

This is likely caused by a malformed conditional statement. It is highly recommended that you fix this error before continuing, but you may continue as-is if you wish.

How can i fix it?

[HeRCuL70]

ok i fixed it.