how can i open a file using a common dialogue instead of doing it this way:

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Dim i As Integer
Dim temp As String
i = 0
CountAges = 0

Open "a:\data.txt" For Input As #1

i = i + 1
Input #1, Names(i), Ages(i)
CountAges = i
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how do bring up the open dialogue box instead of accessing the file directly????