Sorry the title of the question is little confusing. Basically what I want is:
I am working on a php website which is designed for publishing advertises. User can pay some money & they can post their ad on the website. Now I want to raffle 6 ads i.e 6 ads will be randomly choose by the admin & they will get prizes. These ads will be seen on a website for `2 months` after admin chooses them.
 For that I have created one page where right now I am displaying 6 random records from the database using query : 

`"SELECT * FROM tbl_ad ORDER BY RAND() LIMIT 6"`

This is giving `6` random ads. But now I want to give one button on that page by clicking which these `6` ads will be display. But this button is available for admin. He clicks that `button & 6` random records should display below. And once the 6 random records are displayed they should be displayed their until admin clicks that button & those records should displayed to all visitors. Visitor should not display that button.(I know how to do this). 
 Once the records are displayed on that page selected from the database randomly by clicking that button, that selected ads should not change on page refresh. Only admin can change the random records & once he clicked this button those ads should display all the time until & unless admin clicks that button again.