[程序咨询] hide/show div with 'nid

Hi, 

I want to show/hide div with 'nid' check in read chapter page by using javascript.

Example : Get 'nid' data from this link 'module/novel/read.php?tid=9&nid=3&cid=20' for checking condition.

And the condition is 'If nid=3 ; show div and if nid not = 3 ; hide div'.

Could you help me to write javascript or php code?

If nid=3

{cur:nid=3}Show here{/cur}

If nid！=3

{cur:nid=3}Hide here{/cur}

Wow! it's easily

thank you very much.