problem when working in update panel

i have a custome text box in asp.net using c# it is similar to confirm in javascript ,it has two buttons yes and no. when i working inside form i can easily access the value returned  when click on these buttons ,but when i implement this custome messange text box into update pannel since it has no form element then how here i can access these values...?

Can you post your codes here for your custom TextBox?