Update UI From TextBox Data + Page Load Event

I'm updating the UI of my page when it loads with data from SQL. I have a method that pulls the data and returns a string.

I then need to be able to click the button, update SQL, and update the UI with the new value.

The problem is that each postback refreshes the page. So when I click the button, the new data is reverted back to the original value and then SQL is updated with the old data.

Is there any way I can accomplish this in this manner?

Edit: Never mind. Figured it out just after I posted this. I'm using the page PreRender event to load the initial data.