Set dialog text to the text returned AppleScript

I don't k开发者_JAVA百科now much AppleScript. How would I change a dialog box's text based on the text entered in the text box without repeatedly doing something like this?

display dialog "Enter text in the box to change this message" default answer ""
display dialog (the text returned of the result) default answer "To change the displayed message, enter text in the box"
...

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set this_text to "Enter text in the box to change this message"
repeat
    set this_text to the text returned of (display dialog this_text default answer "To change the displayed message, enter text in the box")
end repeat