image field in gridview

source:

 <asp:GridView ID="GridView1" runat="server" DataKeyNames="eid"
onrowcommand="GridView1_RowCommand" AutoGenerateColumns="False"
CellPadding="4" ForeColor="#333333" GridLines="None">

<asp:ImageButton ID="ImageButton1" ImageUrl=''  runat="server"
Height="48px" Width="39px" />

C# code:

SqlConnection cn = new SqlConnection("server=.;uid=sa;pwd=sa123;database=empdb");
SqlDataAdapter da;
DataSet ds;
protected void Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
gv();
}
}
void gv()
{
da = new SqlDataAdapter("select * from path ", cn);
ds = new DataSet();
da.Fill(ds);
GridView1.DataSource = ds.Tables[0];
GridView1.DataBind();
}