I'm having issue with the code for Programming Project 6 from Chapter 4 of Schneider's An Introduction to Programming Using Visual Basic 10 Ed. I keep getting an "InvalidCastException was unhandled" error from the line bolded in my code below, but I've tried everything I can think of and it's still a problem. Any assistance would be great (sorry for not uploading a shot of the problem, having issues with the file size).

Public Class frmCollegeAdmissions Private Sub txtScore_Leave(sender As Object, e As EventArgs) Handles txtScore.Leave txtPoints.Text = "[" & Str(20 * CDbl(txtScore.Text)) & "]" End Sub

Private Sub btnCalculate_Click(sender As Object, e As EventArgs) Handles btnCalculate.Click

Dim Top, Bottom As Double Dim PtsGPA, PtsSAT, PtsHSQ, PtsCur, PtsGeo, PtsAlum, PtsEssay, PtsLeader, PtsMisc As Double Dim geoTotal As Integer Dim bottomTotal As Double = PtsGeo + PtsAlum + PtsEssay + PtsLeader + PtsMisc Dim score As Double = Top + Bottom geoTotal = 0

PtsGPA = 20 * CDbl(txtScore.Text)

If radioSAT930.Checked Then PtsSAT = 6 ElseIf radioSAT1010.Checked Then PtsSAT = 10 ElseIf radioSAT1200.Checked Then PtsSAT = 11 ElseIf radioSAT1360.Checked Then PtsSAT = 12 Else PtsSAT = 0 End If

If radioHS1.Checked Then PtsHSQ = 2 ElseIf radioHS2.Checked Then PtsHSQ = 4 ElseIf radioHS3.Checked Then PtsHSQ = 6 ElseIf radioHS4.Checked Then PtsHSQ = 8 ElseIf radioHS5.Checked Then PtsHSQ = 10 Else PtsHSQ = 0 End If

If radioCurN2.Checked Then PtsCur = -4 ElseIf radioCurN1.Checked Then PtsCur = -2 ElseIf radioCur1.Checked Then PtsCur = 2 ElseIf radioCur2.Checked Then PtsCur = 4 ElseIf radioCur3.Checked Then PtsCur = 6 ElseIf radioCur4.Checked Then PtsCur = 8 Else PtsCur = 0 End If

Top = PtsGPA + PtsSAT + PtsHSQ + PtsCur

If chkGeoState.Checked Then geoTotal = geoTotal + 10 End If

PtsGeo = geoTotal

If chkAlumLegacy.Checked Then PtsAlum = 4 End If

If chkAlumOther.Checked Then PtsAlum = 1 End If

If chkLead1.Checked Then PtsLeader = 1 ElseIf chkLead2.Checked Then PtsLeader = 2 ElseIf chkLead3.Checked Then PtsLeader = 5 End If

If radioMiscSocio.Checked Or radioMiscAth.Checked Or radioMiscProv.Checked Then PtsMisc = 20 ElseIf radioMiscMen.Checked Then PtsMisc = 5 Else PtsMisc = 0 End If

If bottomTotal < 40 Then Bottom = bottomTotal Else Bottom = 40 End If

lstOutcome.Items.Clear() lstOutcome.Items.Add("Total Score:" & score) lstOutcome.Items.Add("")

If (score >= 100) Then lstOutcome.Items.Add("Admitted") Else lstOutcome.Items.Add("Rejected") End If

End Sub

End Class