Call click event of button who called pop up when model pop up window is closed

[makeUbleed]

I have two buttons viz. save and update. On both buttons, I am opening pop-up window using Model Pop-up extender. The Pop-up has "ok" as close button. Now what I want is when user clicks on the "Ok" button in the pop-up, it should call the OnClick_save() or OnClick_update() depends on the button who called pop-up. That means, when user clicks on save button, it will open pop-up window. After entering password in the pop-up window when user click on the Ok button, it should go to the OnClick_save() event. Same thing should happen for update button. How can I do so...???