Loosing the values of dynamically created textboxes

Depending on an SQL result, I create a list of TextBoxes using PlaceHolder as the container. I also added abutton to save the user input. The problem is when I click on the button to read the user input the postback remove all my controls before I have the chance to read the user input. Do you know how I can read the user input before they are removed. Thank you in dvance