setting a default place for decimals

i have a textbox, named txtPPrice.text where in you can only input numbers.

i want that textbox to convert integers into decimals onleave.

i.e
i input 150
onleave the output should be 1.50

another i.e
i input 10025
onleave the output should be 100.25

as you can see, the last two digit became the decimals.

here is my first lines of code:

Dim a As Decimal
        a = txtPPrice.Text

and i don't know what would be next.

at first i used this code:

If txtPPrice.Text <> "" Then
txtPPrice.Text = txtPPrice.Text & ".00"
End If

but then, i don't achieved the goals i want.
i hope for some help.
ty