Calculating a Square Root in Microsoft .Net with Visual Basic

    Function SquareRoot(ByVal x As Double) As Double
        Dim g As Double
        Dim root As Double
        Dim tmp As Double
        Const epsilon = 0.00001
        'Add some error handling
        Try
            'Start with a guess in the variable g
            g = 2
            Do While True  ' Infinite Loop. The condition can never become false
                'Calculate x / g
                tmp = x / g
                'Calculate (x/g) squared
                tmp = tmp * tmp
                'Check to see how close we are to the answer
                If System.Math.Abs(tmp - x) <= epsilon Then
                    Return x / g    ' Send the answer back to the calling procedure
                End If
                'Recalculate the guess
                g = ((x / g) + g) / 2
                'Start the loop over
            Loop

        Catch           ' Errors end up here
            MsgBox("Unable to calculate square root: " & Err.Description, MsgBoxStyle.Critical, "oops")
        End Try
    End Function

    Function SquareRoot(ByVal x As Double) As Double
        Return Math.Sqrt(x)
    End Function