event in asp.net page ??

Hi ,

I have 2 asp.net pages.
when i click on a button on 1.aspx, i made 2.aspx to open like a model window.

On 2.aspx there are 2 buttons , Ok and Cancel
When i click any one of that the model window closes. storing the button name in a session variable like
              session["button"]= "ok" or  session["button"]= "cancel"

Now my issue is, when the 2.aspx closes, the 1.aspx will be still displayed. In which event of the page(1.aspx) i need to put the code for checking the value of session["button"] ??

i dont have ajax

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