Pointers/doubly linked list/C++

Im making a doubly linked list program. I am having problems with the menu uption INSERT_AFTER. I think using the FIND function is the right go at it but I just dont seem to get it right. (The functions are working fine, I just need help with, how to call the function) Can someone help please?

 void FIND(element* head, int searchedNumber) {

 current = head;
 while (current->next != NULL) {

    if (current->key == iskanoSt) {
        cout << "Num" << searchedNumber<< " found.\n";

}
current = current->next;

}
 }
 void INSERT_AFTER(element * &elem, element* new_el) {
      new_el->prev = elem;
      new_el->next = elem->next;
      elem->next = new_el;
  if (new_el->next != NULL) {
     new_el->next->prev = new_el;
} else
    tail= new_el;
 } 
main (){
 ....
if (choosen== 3) {
   cout<< "insert num:";
   element*f=new element;
cin >> f->key; // The number i insert is working fine. I dont know how to 
//find the element that 
         //that I have to insert after. I tryed to insert the function I 
 //wrote above, but I dont know how or 
         //If it is ever correct.
cout<<"After elemen:";
cin >> searchedNum;
FIND(head, searchedNum);

INSERT_AFTER(?????,f);
}