how to read column names of a excel file

string strFilePath = string.Empty;
string ConnString = string.Empty;
string strCols = string.Empty;
string strRowVal = string.Empty;	   
strFilePath = Server.MapPath("~/upload/csvfiles" );
if (strFileType.ToString().Trim() == ".csv")
{
	ConnString = "Provider=Microsoft.Jet.OLEDB.4.0;Data Source=" + strFilePath + ";Extended Properties=Text;";
}
Conn = new OleDbConnection(ConnString);
Conn.Open();

string tablename = "";
if (strFile.IndexOf('/') > 0)
{
	tablename = strFile.Substring(strFile.LastIndexOf("/") + 1);
}
else
{
	Int32 intLastIndex = 0;
	intLastIndex = strFile.LastIndexOf("\\");
	tablename = strFile.Substring(intLastIndex + 1);
}
DataTable dt = new DataTable();
dt = Conn.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);



OleDbCommand ocmd = new OleDbCommand("SELECT * FROM [" + tablename + "]", Conn);

oda = new OleDbDataAdapter(ocmd);
DataSet dsIn = new DataSet();
oda.Fill(dsIn);
Conn.Close();
foreach (DataColumn DtColumn in dsIn.Tables[0].Columns)
{
	strCols = strCols + DtColumn.ColumnName.Trim() + ":";
}

strCols = strCols.Substring(0, strCols.Length - 1);
strColArr = strCols.Split(':');