data binding issue using ASAX..

using asax i bind data but in view it's showing error interenl server error 500 in console error.......while i return partialview ...

public ActionResult bindpurchasereport(string productid, string dealerid, DateTime? mydate1, DateTime? mydate2)

{

var model = new CartSummary1();

ViewBag.FromDate = "From Date : " + mydate1.Value.ToShortDateString() + "";

ViewBag.ToDate = "To Date :" + mydate2.Value.ToShortDateString() + "";

var DistributorId = "";

if (Session["userid"] != null)

{

DistributorId = Session["userid"].ToString();

}

ViewBag.Name = Session["username"];

var DistributorName = Session["username"].ToString();

int IntProductId = 0;

if (productid != "All")

{

IntProductId = Convert.ToInt32(productid);

}

if (productid == "All")

{

List proli = new List();

model.GetInvoiceData = (from c in db.invoice.ToList()

where c.DistributorId == "Admin"

&& ( c.DistributorName == DistributorName)

&& (c.saledate >= mydate1 && c.saledate <= mydate2)

select new Invoice1

{

id = c.id,

saledate = c.saledate,

saleno = c.saleno,

AdminSaleno = c.AdminSaleno,

customerName = c.customerName,

DistributorName = c.DistributorName,

dispercent = c.dispercent,

paymentmode = c.paymentmode,

dealername = GetDealerName(c.dealerid),

NetAmount = c.NetAmount,

TaxAmount = c.TaxAmount,

}).ToList();

model.GetCartData = (from p in db.cartsummary.ToList()

where p.DistributorId == "Admin"

&& (p.DistributorName == DistributorName)

&& (p.saledate >= mydate1 && p.saledate <= mydate2)

select new CartSummary1

{

id = p.id,

productname = GetProductNameList(p.productid),

AdminSaleno = p.AdminSaleno,

saleno = p.saleno,

DistributorName = p.DistributorName,

customer = p.customer,

productid = p.productid,

Rate = p.Rate,

amount = p.amount,

Quantity = p.Quantity,

}).ToList();

return PartialView("bindpurchasereport", model);

}