How to dynamically adding the "Expires" meta tag

[newtodotnet]

Hi All,
I need to add html meta tag "Expires" which tells the browser when to expire the page. If the user wants to expire a page immediatly we have to use this html tag otherwise page expiration should depend up on the browser settings( Internet explorer has the option called "Check the newer versions of stored pages".
I'll have an check box in my application, if that checkbox is true i've to use the below tag otherwise no need to use this tag.
" <meta http-equiv = "Expires", Contents ="0">"
Hope my problem statement is clear and understandable.
Can anybody help me?

Thanks
newbie