Remove Duplicates from Sorted List I

Given a sorted linked list, delete all duplicates such that each element appear onlyonce.

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode deleteDuplicates(ListNode head) {
		// Start typing your Java solution below
		// DO NOT write main() function
		if(head == null)
			return head;
		ListNode cur = head;
		ListNode next;
		while(cur != null && cur.next != null){
			next = cur.next;
			if(next.val == cur.val){
				cur.next = next.next;
			}
			else{
				cur = cur.next;
			}
		}
		return head;
	}
}