Convert String to Time still having problems

This is the error message I get with the following script, please help? It worked fine for the first few reservations, this is the application Copy of Reservations

form Reservations
{
 field alignment = left

 column
 {
 First_Name
 (
 displayname = "First Name"
 type = text
 width = 200px
 )

 Last_Name
 (
 displayname = "Last Name"
 type = text
 width = 200px
 )

 Phone_Number
 (
 displayname = "Phone Number"
 type = text
 width = 200px
 )

 Email
 (
 type = email
 width = 200px
 )

 Select_Date_Start
 (
 displayname = "Select Date Start"
 type = date
 width = 130px
 on user input
 {
 input.String_Start_Date_Time = input.Select_Date_Start + " " + input.Time_Start;
 input.Select_Date_End = input.Select_Date_Start;
 input.Zoho_Date_and_Time_Start = input.Select_Date_Start.toTime();
 selectedtime = input.Time_Start.toTime("h:mm a");
 input.Zoho_Date_and_Time_Start = input.Zoho_Date_and_Time_Start.addMinutes((selectedtime.getHour() * 60 + selectedtime.getMinutes()));
 input.First_Name_and_Time = input.First_Name + " " + input.Time_Start;
 }
 )

 Time_Start
 (
 displayname = "Time Start"
 type = picklist
 values = {"7:00 AM", "7:30 AM", "8:00 AM", "8:30 AM", "9:00 AM", "9:30 AM", "10:00 AM", "10:30 AM", "11:00 AM", "11:30 AM", "12:00 PM", "12:30 PM", "1:00 PM", "1:30 PM", "2:00 PM", "2:30 PM", "3:00 PM", "3:30 PM", "4:00 PM", "4:30 PM", "5:00 PM", "5:30 PM", "6:00 PM", "6:30 PM", "7:00 PM", "7:30 PM", "8:00 PM", "8:30 PM"}
 width = 206px
 on update
 {
 input.String_Start_Date_Time = input.Select_Date_Start + " " + input.Time_Start;
 input.Select_Date_End = input.Select_Date_Start;
 input.Zoho_Date_and_Time_Start = input.Select_Date_Start.toTime();
 selectedtime = input.Time_Start.toTime("h:mm a");
 input.Zoho_Date_and_Time_Start = input.Zoho_Date_and_Time_Start.addMinutes((selectedtime.getHour() * 60 + selectedtime.getMinutes()));
 input.First_Name_and_Time = input.First_Name + " " + input.Time_Start;
 }
 on user input
 {
 input.String_Start_Date_Time = input.Select_Date_Start + " " + input.Time_Start;
 input.Select_Date_End = input.Select_Date_Start;
 input.Zoho_Date_and_Time_Start = input.Select_Date_Start.toTime();
 selectedtime = input.Time_Start.toTime("h:mm a");
 input.Zoho_Date_and_Time_Start = input.Zoho_Date_and_Time_Start.addMinutes((selectedtime.getHour() * 60 + selectedtime.getMinutes()));
 input.First_Name_and_Time = input.First_Name + " " + input.Time_Start;
 }
 )

 String_Start_Date_Time
 (
 displayname = "String Start Date Time"
 type = text
 private = true
 width = 200px
 )

 Zoho_Date_and_Time_Start
 (
 displayname = "Zoho Date and Time Start"
 type = datetime
 private = true
 width = 130px
 )

 Select_Date_End
 (
 displayname = "Select Date End"
 type = date
 private = true
 width = 130px
 )

 Time_End
 (
 displayname = "Time End"
 type = picklist
 values = {"7:00 AM", "7:30 AM", "8:00 AM", "8:30 AM", "9:00 AM", "9:30 AM", "10:00 AM", "10:30 AM", "11:00 AM", "11:30 AM", "12:00 PM", "12:30 PM", "1:00 PM", "1:30 PM", "2:00 PM", "2:30 PM", "3:00 PM", "3:30 PM", "4:00 PM", "4:30 PM", "5:00 PM", "5:30 PM", "6:00 PM", "6:30 PM", "7:00 PM", "7:30 PM", "8:00 PM", "8:30 PM"}
 width = 206px
 on update
 {
 input.String_End_Date_Time = input.Select_Date_End + " " + input.Time_End;
 input.Zoho_Date_and_Time_End = input.Select_Date_End.toTime();
 selectedtime = input.Time_End.toTime("h:mm a");
 input.Zoho_Date_and_Time_End = input.Zoho_Date_and_Time_End.addMinutes((selectedtime.getHour() * 60 + selectedtime.getMinutes()));
 }
 on user input
 {
 input.String_End_Date_Time = input.Select_Date_End + " " + input.Time_End;
 input.Zoho_Date_and_Time_End = input.Select_Date_End.toTime();
 selectedtime = input.Time_End.toTime("h:mm a");
 input.Zoho_Date_and_Time_End = input.Zoho_Date_and_Time_End.addMinutes((selectedtime.getHour() * 60 + selectedtime.getMinutes()));
 }
 )

 String_End_Date_Time
 (
 displayname = "String End Date Time"
 type = text
 private = true
 width = 200px
 )

 Zoho_Date_and_Time_End
 (
 displayname = "Zoho Date and Time End"
 type = datetime
 private = true
 width = 130px
 )

 Type_of_Ride
 (
 displayname = "Type of Ride"
 type = picklist
 values = {"1/2 Hour tour of Facility", "Public 1 Hour Ride", "Public 1.5 Hour Ride", "Public 2 Hour Ride", "Public 3 Hour Ride", "Private 1 Hour Ride", "Private 1.5 Hour Ride", "Private 2 Hour Ride", "Private 3 Hour Ride", "Private Lesson", "Public Lesson", "Kids Lesson", "Bulk Lesson (Public lessons)", "Groupon Family Ride", "Groupon Romantic", "Gift Certificate 1 hour", "Gift Certificate 1.5 hour", "Gift Certificate 2 hour", "Boarding", "Pony Party"}
 width = 206px
 )

 Number_of_Riders
 (
 displayname = "Number of Riders"
 type = number
 width = 100px
 )

 Cost_to_Customer
 (
 displayname = "Cost to Customer"
 type = USD
 width = 100px
 )

 Guides
 (
 type = text
 width = 200px
 )

 Volunteers
 (
 type = text
 width = 200px
 )

 Ride_Status
 (
 displayname = "Ride Status"
 type = picklist
 values = {"Closed", "Canceled", "Rescheduled", "No Show", "Booked"}
 width = 206px
 )

 }
 column
 {
 Riders_Names_Wieghts_Ages
 (
 displayname = "Riders Names Wieghts Ages"
 type = textarea
 height = 100px
 width = 200px
 )

 Street_Address
 (
 displayname = "Street Address"
 type = text
 width = 200px
 )

 City
 (
 type = text
 width = 200px
 )

 State
 (
 type = text
 width = 200px
 )

 Zip
 (
 type = number
 width = 100px
 )

 Discount_Cost
 (
 displayname = "Discount Cost"
 type = USD
 width = 100px
 )

 Discount_Reason
 (
 displayname = "Discount Reason"
 type = textarea
 height = 100px
 width = 200px
 )

 Notes
 (
 type = textarea
 height = 100px
 width = 200px
 )

 First_Name_and_Time
 (
 displayname = "First Name and Time"
 type = text
 private = true
 width = 200px
 )

 }
 actions
 {
 on add
 {
 on load
 {
 hide Select_Date_End;
 //hide Zoho_Date_and_Time_Start;
 hide String_Start_Date_Time;
 hide Zoho_Date_and_Time_End;
 hide String_End_Date_Time;
 hide First_Name_and_Time;
 }
 Submit
 (
 type = submit
 displayname = "Submit"
 PreSubmit = "<?xml version=\"1.0\" encoding=\"UTF-8\"?><preoncommit><sendmail><language><![CDATA[English]]></language><bcc><![CDATA[\"teddi4god@msn.com\"]]></bcc><enabled><![CDATA[true]]></enabled><subject><![CDATA[HorseBack Ride Reservation]]></subject><conttype><![CDATA[HTML]]></conttype><from><![CDATA[zoho.adminuserid]]></from><to><![CDATA[input.Email]]></to><message><![CDATA[Thank you for reserving a ride with Rescue Ranch Saddle Club. Please arrive a 1/2 hour early to give time to prepare for ride and that it can go out on time. Your ride starts at <%=Select_Date_Start%>" "<%=Time_Start%>  and ends at <%=Select_Date_Start%> " "<%=Time_End%>. Your type of ride is a <%=Type_of_Ride%>. If you have any questions please call reservations at 503 871 0549. Wear pants and closed shoes, boots are encouraged. No sandals or flip flops, no shorts will be allowed for wear during horseback rides. 95% of proceeds benefit the horse rescue and youth programs. Thanks! Please note that we prefer cash, but checks are accepted. Address is 44425 Thomas Creek Dr. Scio Oregon, 97347 Look for the tan barn on the left hand side of the road ]]></message></sendmail></preoncommit>\n"
 )
 Reset
 (
 type = reset
 displayname = "Reset"
 )
 }
 on edit
 {
 Update
 (
 type = submit
 displayname = "Update"
 )
 Cancel
 (
 type = cancel
 displayname = "Cancel"
 )
 }
 }
}