protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
        {
            if (e.Row.RowType == DataControlRowType.DataRow )
            {
                Label lb=e.Row.FindControl("lbName") as Label;
                e.Row.Cells[1].Attributes.Add("onclick ", " window.returnValue='" + lb.Text.Trim() + "';window.close();");
            }
        }

protected void GridView1_RowEditing(object sender, GridViewEditEventArgs e)
        {

            GridView1.EditIndex = e.NewEditIndex;
            bind();
        }

<script type="text/javascript">
  function chose() {
  var hdc = window.showModalDialog("bunit.aspx", "newwindow", "resizable:no;scroll:yes;status:no;dialogLeft=380px;dialogTop=500px;dialogWidth=300px;dialogHeight=250px;center=no;help=no");
  document.getElementById("<%=GridView1.ClientID%>").rows[document.getElementById("<%=GridView1.ClientID%>").rows.length - 1].getElementsByTagName("input")[3].value = hdc;
  }

if (e.Row.RowType == DataControlRowType.DataRow && GridView1.EditIndex==-1)