Asp. NET export data to Excel and output

ASP tutorial. NET Export data to Excel and output
public void Import ()

{
if (This.ddl_task.selectedvalue = "-1")
{
Function.script.alert ("Please choose a theme!") ");
Return
}
String savepath = Server.MapPath ("sql\");

if (fileup1.hasfile)
{
Excelengine excelengine = new Excelengine ();
IApplication application = Excelengine.excel;
Savepath + = Fileup1.filename;
Fileup1.saveas (Savepath);
Iworkbook workbook = Excelengine.excel.workbooks.open (Savepath);
Iworksheet Sheet1 = workbook.worksheets[0];
for (int i = 0; i < sheet1.rows.length-1; i++)
{

if (!ifexistinblacklist (sheet1.range["E" + convert.tostring ((i + 2))].value2.tostring (), sheet1.range["F" + Convert.ToString ((i + 2))].value2.tostring ())
{
using (oracleconnection connection = new OracleConnection (configurationmanager.connectionstrings[) Dvteconnectionstring "].tostring ()))
{
String sql = "INSERT into Dc_visituser (Customerid,cust_name,cust_addr,addrcode,mobilephone,homephone,taskid)";
SQL + = "VALUES ('" + sheet1.range["a" + convert.tostring ((i + 2))].value2 + "'";
SQL + + ", '" + sheet1.range["B" + convert.tostring ((i + 2))].value2 + "'";
SQL + + ", '" + sheet1.range["C" + convert.tostring ((i + 2))].value2 + "'";
SQL + + ", '" + sheet1.range["D" + convert.tostring ((i + 2))].value2 + "'";
SQL + + ", '" + sheet1.range["E" + convert.tostring ((i + 2))].value2 + "'";
SQL + + ", '" + sheet1.range["F" + convert.tostring ((i + 2))].value2 + "'";
SQL + + "," + this.ddl_task.selectedvalue;
SQL + = ")";
OracleCommand command = new OracleCommand (sql, connection);
Connection.Open ();
Command.executenonquery ();

}
}
}

Excelengine.thrownotsavedondestroy = false;
Excelengine.dispose ();
This.bindgridview ();
}

}