thread not started

[C# Programming]

when i start thread it displays "thread is not started"
some times nothing is diplayed nothing is happening
can anyone help....
code is like this

class class1
{
class2 obj=new class2();
thre=new thread(new threadstart(obj.run));
}
class class2
{
public void run()
{
}
}
what can be the problem

This code was posted by me...