search is not working

Question

my text box search code

 public void gridsearch()
        {

            ClassSp spclass = new ClassSp();
            DataTable dtblc = new DataTable();
            dtblc = spclass.classSearch(decserch);
            gvclassreport.DataSource = dtblc;
        }

        protected void txtclassName_TextChanged(object sender, EventArgs e)
        {
            if (txtclassName.Text != string.Empty)
            {
                decserch = txtclassName.Text;
                gridsearch();

            }
            else
            {
                gridfill();
            }
        }