SQL database from c#.net

i haev a problem in my c# program i keep getting an exception
the point of the program is to: Write a Windows form application that displays the items on order for which there is insufficient stock in inventory to process the orders.  When the button is pressed, the following information about out-of-stock items should be displayed: Item number, Item description, Quantity ordered, Quantity on hand.

i created a class invalid that stores the data values nessisary

unsafe class ぬるぽ{
 static int Main(){
  int i=0;
  int *p=(int *)i;
  return *p;
 }
}