NULL REFERENCE EXCEPTION:object reference not set to an instance of an object.
Any ideas how to solve it?
Set an instance of an object to the object reference.
ok but how 
tell me step by step if you can.Im new with this ne.
click on the error it will take you to the line where the null object is and then try to find out which either by looking at it and realizing it or by having a debug log in front thta prints (obj == null) for all objects to see which one returns true there