Using a dropdownlist to insert data into SQL database

Hello friends,
Please I am having issues inserting selected values from my dropdownlist into a database. Please note that my dropdownlist is databound to a table in my database(meaning it gets dynamically populated with values from a column in the database). Below is my code

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Imports System.Data
Imports System.Data.SqlClient
Public Class Registration_Form
Inherits System.Web.UI.Page

Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
txtDate.Text = DateTime.Now.ToShortDateString
End Sub

Protected Sub btnSubmit_Click(sender As Object, e As EventArgs) Handles btnSubmit.Click
Dim con As New SqlConnection(ConfigurationManager.ConnectionStrings("ConnectionString").ConnectionString)
Try

'Dim cmd As New SqlCommand("INSERT INTO Contacts (SurName,FirstName,Gender,Age,Email,Phone,Occupation,State_of_Residence,State_of_Origin,Date) VALUES ('" + txtSurname.Text + "','" + txtFirstname.Text + "','" + txtGender.Text + "','" + txtAge.Text + "','" + txtEmail.Text + "','" + txtPhone.Text + "','" + txtoccupation.Text + "','" + txtResidence.Text + "','" + txtOrigin.Text + "','" + txtDate.Text + "')", con)
Dim cmd As New SqlCommand("INSERT INTO Contacts (SurName,FirstName,Gender,Age,Email,Phone,Occupation,StResidDropDownList,StOrgDropDownList,Date) VALUES ('" + txtSurname.Text + "','" + txtFirstname.Text + "','" + txtGender.Text + "','" + txtAge.Text + "','" + txtEmail.Text + "','" + txtPhone.Text + "','" + txtoccupation.Text + "',' " + StResidDropDownList.SelectedValue + " ',' " + StOrgDropDownList.SelectedValue + " ','" + txtDate.Text + "')", con)

cmd.ExecuteNonQuery()

Catch ex As Exception
con.Close()
End Try
End Sub

End Class
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i am sure my problem is with the dropdownlists (StResidDropDownList.SelectedValue and StOrgDropDownList.SelectedValue). Because when I take it off , I can insert values into the database.