[jQuery] select all grandchildren of a div

[Krish]

Hey All,

I have to select all my grandchildren of parent div. only the
grandchildren not either of children or great grandchildren.

 <div id="parent" class="parent" >
    <div  id="child" class="child">
           <div  id="grand_child_1" class="grandchild" > </div>
                   <div  id="great_grand_child_1"
class="greatgrandchild" > </div>
                   <div  id="great_grand_child_2"
class="greatgrandchild" > </div>
                     .
                     .
                      .
                    <div  id="great_grand_child_n"
class="greatgrandchild" > </div>
         <div  id="grand_child_2" class="grandchild" > </
div>
                   <div  id="great_grand_child_1"
class="greatgrandchild" > </div>
                   <div  id="great_grand_child_2"
class="greatgrandchild" > </div>
                     .
                     .
                      .
                    <div  id="great_grand_child_n"
class="greatgrandchild" > </div>
         <div  id="grand_child_3" class="grandchild" > </div>
        .
        .
        .
        .
        <div  id="grand_child_n" class="grandchild"> </div>
   </div>
</div>

How can i  achieve this using jquery?

Thanks in advance....

regards,
krish