The following code doesn't execute and doesn't give any message. I'd be glad if someone could edit it for me.

Try
Dim qry, subject As String
If rbnCore.Checked = True Then
subject = "Core"
Else : subject = "Elective"
End If
qry = "Update ProgramDetails.Subjects set SubjectName=@SubjectName,SubjectType=@SubjectType,UserID=@UserID,UserName=@UserName,Password=@Password where SubjectCode='" & txtSubjectCode.Text & "'"
cmd = New SqlCommand(qry, cn)
cmd.Parameters.Add(New SqlParameter("@SubjectCode", txtSubjectCode.Text))
cmd.Parameters.Add(New SqlParameter("@SubjectName", txtSubName.Text))
cmd.Parameters.Add(New SqlParameter("@SubjectType", subject))
cmd.Parameters.Add(New SqlParameter("@UserID", txtUserName.Text))
cmd.Parameters.Add(New SqlParameter("@Password", txtPassword.Text))
cmd.ExecuteNonQuery()
MessageBox.Show("Record successfully updated", "Updated", MessageBoxButtons.OK, MessageBoxIcon.Information)
showgrid()
Catch ex As Exception
End Try