IF clause based on Database value being found??

hi,
I am querying a text file and have the working code below.

 protected void Button1_Click(object sender, EventArgs e)     {         //create instance foe oledb connection class         OleDbConnection con = new OleDbConnection();                  //Your datasource Location path currently i placed csv file in server location         string dsource = (Server.MapPath("test.csv"));         //Put your datasource path in the connection string for example if you have csv files in C:\ directory change datasource= C:\         string constr = @"Provider=Microsoft.Jet.OLEDB.4.0; Data Source=C:\XXX; Extended Properties=" ...