So the gui is suppose to edit when you click it but when you do it removes all of it and you have to reset everything.
Even though this is not a scripting question, I will help anyway.
I'm guessing you mean that the text clears when you click on it, but you still want to edit it.
If you want to make it not clear when you click it turn off "Clear on focus" in properties.
If you do not want to be able to edit the text while playing you must use Text labels not Text boxes.