add a search field which search for values of specific field in a content type I've created a content type "Submission", which have many fields. One of them is "ID". 

Now, I need a search box (apart from regular search box). It should be searched with ID value, it should display search result of content which have this ID value. 

Any suggestions please.
You can create a separate Search Page using Views: Here is a tutorial (http://webwash.net/tutorials/how-create-search-pages-using-views-drupal-7)

Views:


  You like the default front page view, but you find you want to sort it differently.
  You like the default taxonomy/term view, but you find you want to sort it differently; for example, alphabetically.
  You use /tracker, but you want to restrict it to posts of a certain type.
      You like the idea of the 'article' module, but it doesn't display articles the way you like.
      You want a way to display a block with the 5 most recent posts of some particular type.
      You want to provide unread forum posts.
      You want a monthly archive similar to the typical Movable Type/Wordpress archives that displays a link to the in the form of
  Month, YYYY (X) where X is the number of posts that month, and
  displays them in a block. The links lead to a simple list of posts for
  that month. 
  
  Views can do a lot more than that, but those are some of the obvious
  uses of Views.