Percent Field Rounds To Whole Number

I am having a problem retaining the right 2 decimal places in my datagrid field. I have it defined as a decimal but when the update happens it rounds the decimal places back to .00.

Dim NewMarkup As String

'retrieve the new values

NewMarkup = CType(e.Item.FindControl("Markup"), TextBox).Text

'create the ado.net objects

Dim command As New SqlCommand("UpdatePricing", connection)

command.CommandType = CommandType.StoredProcedure

'parameters

command.Parameters.Add("@Markup", SqlDbType.Decimal, 5)

command.Parameters("@Markup").Value = CDec(NewMarkup)

Thanks!