Textbox textchanged event

I have a simple form with one label, one button and one text box. When button is clicked, just update  the label with current time. When we enter a number in the textbox and press enter, we will save this number in database.
What I am doing now is in buttonclicked event, update the label. In textbox textChanged event, save data.
The problem is if I enter a number in the textbox but do not press enter, then hit the button. Both button click and text changed events will be raised and this number will be saved into database.
Is there any way I can avoid this? number should be saved only when enter is pressed.
Thanks for your help

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