Parameters In Query The Database Doesn't Update In C# And Mysql Using Odbc

when i specify values in my update query the query works fine and the database gets updated, but when i use parameters in my query the database does not update here is the code i have written

try
{
OdbcConnection MyConnection = new OdbcConnection(ConfigurationManager.ConnectionStrings["myconn"].ConnectionString);
MyConnection.Open();
String MyString = "UPDATE orddetpabak SET jud1=@jud1,jud2=@jud2,jud3=@jud3,adv=@adv where fil_no=@fil_no AND orderdate=@orderdate";
OdbcCommand MyCmd = new OdbcCommand(MyString, MyConnection);
String j1=DropDownList4.SelectedValue;
String j2=DropDownList5.SelectedValue;
String j3=DropDownList6.SelectedValue;
String j4=TextBox4.Text;
String j5 = HiddenField1.Value;
String j6 = TextBox3.Text;
MyCmd.Parameters.AddWithValue("@jud1",j1);
MyCmd.Parameters.AddWithValue("@jud2",j2);
MyCmd.Parameters.AddWithValue("@jud3",j3);
MyCmd.Parameters.AddWithValue("@adv",j4);
MyCmd.Parameters.AddWithValue("@fil_no",j5);
MyCmd.Parameters.AddWithValue("@orderdate",j6);
Response.Write(DropDownList4.SelectedValue);
Response.Write(" " + DropDownList5.SelectedValue);
Response.Write(" " + DropDownList6.SelectedValue);
Response.Write(" " + TextBox4.Text);
Response.Write(" " + HiddenField1.Value);
Response.Write(" " + TextBox3.Text);
MyCmd.ExecuteNonQuery();
//MyConnection.Close();
}
catch(Exception epp)
{
Response.Write(epp);
}