dropdownlist selected value is not saved in the database

Question

  In run mode as follows

Name                  textbox1

Designation      Courseofficer (Dropdownlist)
                        Prinicpal
                        Director


Save(Buuton)
in the designation column three values are there in the dropdownlist


When user type the name ram in textbox1 and select the designation from the dropdownlist.
Suppose i am selecting the Courseofficer from the dropdownlist and click Save button records are saved.

but i am selecting the courseofficer from the dropdownlist only. But in database
last value Director is saved in the database.


Save button code as follows
Sql = "insert into Designations values('" + txt_name.Text + "','" + ddldesg.SelectedValue.ToString() + "')";
SCon.ExecSql(Sql);
LblErr.Text = "Record Inserted Successfully";
SCon.Con.Close();

In database records as follows
ID        Name             Designations
1           Ram              Director

please help me what is the problem in my above code.