textbox.text and label.text won't change dynamically

I have an asp page with a textboxes, labels and other controls.  I cannot get the .text to change in any of these controls.  I click on button which I execute code that I expect to update the text but it doesn't work.  Something like Textbox1.text = "Hello"  Are there page level properties/settings I should look at?  I am perplexed an looking for a place to start.  I will provide more information as needed.  I just don't know where to start.
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