How to search something in NSMutableDictionary

Hello I have a NSMutableArray like this

Contactarray (

{

   "firstNAme"="name1"
   "lastName"="name2"
   "phoneNumber"="12345678902";
}

{

   "firstNAme"="name1"
   "lastName"="name2"
   "phoneNumber"="12345678902";
}

I want to search the person when I type the person name in my UITextField. Then the filtered UItableView should be loaded. This NSMutableArray contains NSMutableDictionaries.

How can I find the matching object from these objects?

Lets say I want to search all name1 people. Then I want to find all the objects containing "name1" and those objects should fill to another array to load the UITableview

Please help me. Thanks.