response.write in my code and on postback it is breaking the intended render

I have a response.write in my code and on postback it is breaking the intended render of my page causing large font output...
Does anyone know how I can prevent this from happening. I have already spent many hours working around the issue of getting java popup boxes to output correctly to interact with the user, a particular requirement of this porject. Now I need to prevent the font from changing size on the Postbacks.
 
Thanks,
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