How to save data from Datagridview Directly to Database using col.Header

[Rahmania03]

Hello Friends,
I m Developing an windows form application. i have a winform on which i have datagridview and i am saving the data to Sql Server database
from datagridview directly . i m using the following code for connecting & saving data of datagridview to database using button click . though i am suscessful
in connecting to database and also saving data to database after my data is saved i get following error
"Object reference Not set to Instance of object" and after clicking on ok i get second error message
"Must declare the scalar variable @Jour" which i have already declared

following are the names of controls and database object

"dgJrn"l is Datagridview
"JournalEntry " is Table in Database named "TMSDB"
"JournalType "is Column in "JournalEntry" Table
"JournalHead" is Column in Datagridview
and "@jour" is parameter

Waiting for your help

 private void btnRecord_Click(object sender, EventArgs e)
        {
            SqlConnection cn = new SqlConnection(@"Data Source=(local)\SQLEXPRESS;Integrated Security=true;Initial Catalog=TMSDB");
            foreach (DataGridViewRow dr in dgJrnl.Rows)
             {
                 SqlCommand cmd = new SqlCommand("Insert into JournalEntry (JournalType) values(@Jour)", cn);

                     cmd.Parameters.AddWithValue("@Jour", dr.Cells["JournalHead"].Value.ToString ());


                 cn.Open();
                 try
                 {
                     int res = cmd.ExecuteNonQuery();
                     if (res > 0)
                     {
                         MessageBox.Show("Data Stored");
                     }
                 }
                 catch (Exception ex)
                 {
                     MessageBox.Show(ex.Message);
                 }
                 finally
                 {
                     cn.Close();
                 }
                 }