Write a program to compute tips for services rendered.  The program should request the person’s occupation, the amount of the bill, and the percentage tip as input and pass this information to a Sub procedure to display the person and the tip.  A sample run is shown in the figure below.

Suggested Control Names and Attributes:

Name Property	Text Property	Control Type	Notes
frmTipping	Gratuities	Form	Holds Controls
txtOccupation		TextBox	Captures occupation
txtBillAmount		TextBox	Captures total amount of bill
txtPercentage		TextBox	Captures percentage of tip
btnCompute	Compute Tip	Button	Triggers event to display results
txtOutput		TextBox	Displays output.  Read only property set to true.

Hints:

• Create a function to receive and validate input
• Create a sub procedure to calculate and display the results.

Write the Code:

' Project: Tipping
' Description: Receives input from user and calculates the tip.

Public Class Tipping
    ' Declare public variables
    Dim occupation As String
    Dim billAmount As Double
    Dim percentage As Double
    Dim tipAmount As Double

    Private Sub btnCompute_Click(sender As Object, e As EventArgs) Handles btnCompute.Click
        If InputIsValid() = True Then
            CalculateValue()
        Else
            MessageBox.Show("Missing or invalid input. Please try again.")
        End If
    End Sub

    Function InputIsValid() As Boolean
        Dim valid As Boolean = True
        occupation = txtOccupation.Text
        If (occupation = "") Then
            MessageBox.Show("Occupation cannot be blank.")
            valid = False
        End If
        If IsNumeric(txtBillAmount.Text) Then
            billAmount = CDbl(txtBillAmount.Text)
            If (billAmount < 0) Then
                MessageBox.Show("Bill amount cannot be negative.")
                valid = False
            End If
        Else
            MessageBox.Show("Bill amount must be numeric.")
            valid = False
        End If
        If IsNumeric(txtPercentage.Text) Then
            percentage = CDbl(txtPercentage.Text)
            If (percentage < 0) Then
                MessageBox.Show("Percentage cannot be negative.")
                valid = False
            End If
        Else
            MessageBox.Show("Percentage must be numeric.")
            valid = False
        End If
        Return valid
    End Function

    Sub CalculateValue()
        tipAmount = billAmount * (percentage / 100)
        txtOutput.Text = ("Tip the " & occupation & " " & tipAmount.ToString("C"))
    End Sub
End Class