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Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click Dim loanAmount As Integer = AmountBorrowedBox1.Text 'create arrays to hold interest rate and length of loan Dim Interest() As Decimal = {5.35, 5.5, 5.75} Dim term() As Integer = {7, 15, 30} 'establish value of radio buttons If InterestRate1.Checked = True Then apr = Interest(0) End If If InterestRate2.Checked = True Then apr = Interest(1) End If If InterestRate3.Checked = True Then apr = Interest(2) End If If Term1.Checked = True Then length = term(0) End If If Term2.Checked = True Then length = term(1) End If If Term3.Checked = True Then length = term(2) End If payment = (loanAmount * Math.Pow((apr / 12) + 1, (term)) * apr / 12) / (Math.Pow(apr / 12 + 1, (term)) - 1) 'apply payment to textbox TextBox2.Text = "$" + payment.ToString 'validate input If IsNumeric(AmountBorrowedBox1.Text) = False Then MsgBox("Loan amount must be numeric. Please enter a valid loan amount.", MsgBoxStyle.Exclamation) AmountBorrowedBox1.Clear() AmountBorrowedBox1.Focus() End If End Sub