Hi,
First Check whether code Remarks filed has value or not.
If You get the Result has nothing then simply display Empty else display the Database value..
if (string.IsNullOrEmpty(dx.Tables["data"].Rows[0][0].ToString()) == false)
{
txtRemarks.text = dx.Tables["data"].Rows[0][0].ToString())
}
else
{
txtRemarks.text =""
}