how i can fix this format that get highlighted?

trying to create a page and that's my Default.aspx file

19 B 20 21 22 23 End Sub O references Protected Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.click Dim myqty As Integer Dim Resturant As Double 36 de Din subtti As Double 26 Dim tax As Double 27 Din taxttl As Double 28 Din total As Double 29 30 myaty - Cint(txtQuantity.Text) 31 Lesturantcobi (Food SelectedValue) 32 A InvalidCastException was unhandled by user code 33 An exception of type "System.InvalidCastException' occurred in tax = e.es Microsoft.VisualBasic.dil but was not handled in user code 35 subtt) = (myqty Resturant) Additional information: Conversion from string *8:50" to type "Double' is not 37 taxttl = tax subttl valid. 38 total = subttl + taxtti Troubleshooting tips: 39 Make sure the source type convertible to the destination type lblTotal.Text = total.ToString("c") When casting from a number the value must be a number less than infinity 1stSummary.Items.Add("Event Info") Get general help for this exception 43 1stSummary.Items.Add("*** Search for more Help Online 44 1st Summary.Items.Add("Name: & txtNe Exception settings: Break when this exception type is user-unhandled Actions: View Detail Name Value Copy exception detail to the clipboard Food System.Web.UI.WebControls.Radic Open exception settings Food SelectedValue "8:50" Me (ASP.default_aspx) _Default Resturant 0 Double 1 Integer D txtQuantity (System.Web.UI.WebControls.TextBox) System.V Ju txtQuantity.Text "1" Autos Locals Watch 1 Call Stack Breakpoints Exception Settings Com 82 00% Autos D myaty 9 - String INS 20 End Sub Oreferences Protected Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.click Din myqty As Integer Din Resturant As Double View Detail Din subttl As Double Din tax As Double Di taxttl As Double Dia total As Double 26 27 28 29 3e 33 32 33 myqty = Cint(txtQuantity.Text) Mesturant Dol(Food Selectedvalge) Exception details System.InvalidCastException > Data Helplink Result > InnerException Message Source StackTrace > TargetSite rConversion from string -8.50 to type Double System Collections List Dictionaryinternal Nothing 2147467262 input string was not in a correct format, Conversion from string -8.50 to type Double Microsoft Visual Basic at Microsoft.VisualBasic.Complerservices Conv Double ToDouble System String System Global tax 0.05 subtti - (mygty. Resturant) taxttl .taxsubttl total = subtel + taxtel 38 40 1b1Total.Text = total.ToString(*c) 1stSummary.Items.Add("Event Info") OK 1stSumary.Items.Add("* IstSummary.Items.Add("Name: * & txtNa Exception stange 100% Break when this exception type is user-unhandled Actions: Autos View Detail Name Value > Food Copy exception detail to the clipboard (System.Web.UI.WebControls.Radic Food Selected Value *8:50 Open exception settings > Me (ASP default_aspx? _Default Resturant 0 Double myqty Integer D AtxtQuantity (System.Web.UI.WebControls TextBox) System. txtQuantity Text "1" - String Autos Locals Watch 1 Call Stack Breakpoints Exception Settings Command Windo ( Ready in 31 Col 9 Ch 9 0 Type here to search O i CE C 8 2 references Partial Class _Default Inherits System.Web.UI. Page ON e Oreferences Protected Sub Page_Load(sender As Object, e As EventArgs) Handles Me.Load End Sub O references Protected sub btnClear_Click(sender As Object, . As EventArgs) Handles btnClear.Click txtName.Text = txtAddress.Text.** txtPhone. Text txtCity.Text txtState. Text txtZip.Text = "" 16.Message.Text... HH 11 12 13 14 15 16 17 18 19 txtName. Focus() End Sub O references B Protected Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click Dim myqty As Integer Dim Resturant As Double Dim subtti As Double Dim tax As Double Dim taxttl As Double Dim total As Double 21 22 23 24 25 26 27 28 29 38 31 32 33 34 35 36 37 myaty - Cint(txtQuantity.Text) Resturant - Cobl(Food. SelectedValue) tax = 8.65 subtti - (myqty Resturant) taxtti = tax subtti total St1 avt1 24 25 26 27 28 29 Din subtt? As Double Din tax As Double Dim taxtt1 As Double Dim total As Double myqty Cint(txtQuantity.Text) Resturant . cob1(Food SelectedValue) 31 32 33 34 35 36 37 38 39 40 tax 0.05 subtt1 - (maty Resturant) taxtti tax subtt2 total subtt1 taxtti ab Total. Text . total. Tostring("e") IstSummary.Items.Add("Event Info") 1stSummary.Items.Add("****** ****") 1stSummary.Items.Add("Name: "& txtName.Text) IstSunary.Items.Add("Phone: "& txtPhone. Text) 42 46 47 48 49 50 51 52 53 Istunnary.Items.Add("**** IstSummary.Items.Add("Tax: 5X") 1stSummary.Items.Add("Final Price: $" & 1b1Total. Text) 1stSummary.Items.Add(" End Sub O references e 54 55 56 Protected sub btnConfirm_Click(sender As object, e As EventArgs) Handles btnConfirm.Click IbiMessage.Text. "Thanks for your order! It will be processed soon." End Sub O references Protected Sub txtCity_TextChanged(sender As Object, . As EventArgs) Handles txtcity.TextChanged B 57 58 End Sub End Class 60 61