Merge sort help

[enigma08]

I need to merge sort two linked lists, each has a header and the elements are all ints.

I've tried adapting some generic code, but have run into a problem - errors that are similar to this one:

split(AlgSet.LL AlgSet) in AlgSet.LLAlgSet cannot be applied to (Node<java.lang .Integer>)

I see how that is happening as I'm giving it an element next instead of an actual list. Can someone help me out? I don't think it'll take much to fix it, and I am not that skilled in Java.

public LLAlgSet merge (LLAlgSet list1, LLAlgSet list2) {

	if (list1 == null) return list2;
	if (list2 == null) return list1;
	if (list1.element < list2.element) { 			
		list1.next = merge (list1.next, list2);
		return list1;
	} // end if
	else {
		list2.next = merge (list1, list2.next);
		return list2;
	} // end else*/

}

    public LLAlgSet merge_sort (LLAlgSet list1) { 
	if (list1 == null || list1.next == null)
           return list1; // checks for empty or single list
	LLAlgSet list2 = split (list1);
	list1 = merge_sort (list1);
	list2 = merge_sort (list2);
	return merge (list1, list2);
        }

    public LLAlgSet split (LLAlgSet list1) {
	if (list1 == null || list1.next == null) return null;
	LLAlgSet list2 = list1.next;
	list1.next = list2.next;
	list2.next = split (list2.next);
	return list2;
}