public int search (int key)
    {
        Node temp = head;
        boolean isFound = false;
        int index = 1;

while ((temp != null) && (isFound == false))
        {
            if (temp.data == key)
            {
                isFound = true;
            }
            else
            {
                temp = temp.next;
                index++;
            }
        }
        
}
if (isFound == true)
            return index;
        else
            return -1;
    }