search value in gridview from text box

i'm trying to pass value from textbox filter the gird view table. but when pass data  grid view does not show any thing
code as follow

protected void Page_Load(object sender, EventArgs e)         {             SqlConnection con = new SqlConnection(strcon);             SqlCommand cmd = new SqlCommand("Select studentID[Student Name] from StudentDetail ", con);             SqlDataAdapter daGrid = new SqlDataAdapter(cmd);             DataSet ds = new DataSet();             daGrid.Fill(ds);             gvStudent.DataSource = ds.Tables[0]; ...