Fetch Records Between Two Dates From Key_rec Table?

I am using VB.NET as front end and oracle 9i as db my problem is this i am writing this query to fetch records between two dates from Key_rec table but the problem is this when i enter the report using dtpicker1 and dtpicker2 these two values goes in txtfrom and txtto then i press view report button but it shows blank report but when i enter the date manually from key board it works fine its mean nothing is wrong with the query there is some problem with the dtpicker1 and dtpicker2 here is the query on btnrep[code].....