Object reference not set to instance of an object error in sharepoint job feature

Hi all,

I am using the below code for deactivating the sharepoint feature but I am getting the error object reference not set to instance of an object error. Can anyone help me to resolve this issue please..

  foreach (SPJobDefinition job in site.WebApplication.JobDefinitions)
                    {

                        if (job.Name == List_JOB_NAME)

                            job.Delete();

                    }