binding with datatset

Question

 
tXtSearch.Text='300*400'

 private void tXtSeach_TextChanged(object sender, EventArgs e)
        {
            try
            {


               if (dgv_Search.DataSource.Equals(prodmastBindingSource))
                {
             tXtSeach.Text.Trim().ToUpper());


                  prodmastBindingSource.Filter = String.Format("Description like '%{0}%'", tXtSeach.Text.Trim().ToUpper());
                }
            }
            catch { } 
        }


Error in Like operator: the string pattern '300*400%' is invalid.