List<int> bidIds = new List<int>();
List<ExportBidGc> pBidList = new List<ExportBidGc>();
///////////// pBidList needs to be populated with data//////////////

GridView Grid1 = new GridView();
Grid1.DataSource = pBidList; //now set datasource as pBidList
Grid1.DataBind();
Label info = new Label();
info.Text = "<span style='background-color:Yellow'>Project Name: "
+ proNameLabel.Text + "<br/>" + proComNameLabel.Text <br/></span>";

Response.Clear();
Response.Buffer = true;
Response.ContentType = "application/vnd.ms-excel";
Response.AddHeader("Content-Disposition", "Attachment;filename=Bids.xls");
Response.Charset = "";

this.EnableViewState = false;
System.IO.StringWriter oStringWriter = new System.IO.StringWriter();
System.Web.UI.HtmlTextWriter oHtmlTextWriter = new System.Web.UI.HtmlTextWriter(oStringWriter);
info.RenderControl(oHtmlTextWriter);
Grid1.RenderControl(oHtmlTextWriter);

Response.Write(oStringWriter.ToString());

Response.End();

hope it helped u a lot.