/**
  * This is the node for the stack.
	* It includes an object field to store the value, and a reference to
	* store the  pointer to the next node.
	*
	* @author Rachel Chen 0122070
	* @version 1.0    2003/3/22
	*/
public class StackNode  
{
  /** The variable to store the value of the node. */
	private Object element;

	/** The variable to store the reference to the next node. */
	private StackNode next;
	
	/**
	  * The constructor for this class.
		* It initializes the fields element and next to null.
		*/
	public StackNode()
	{
		element = null;
		next = null;
	}
  
	/**
	  * The constructor for this class. <p>
		* It initializes the fields element and next to the parameters given.
		* 
		* @param it The value for the node.
		* @param nextEle The reference to the next node.
		*/
	public StackNode( Object it, StackNode nextEle )
	{
		element = it;
		next = nextEle;
	}	
  
	/**
	  * The constructor for this class. <p>
		* It initializes the fields element to the parameters given and next to null.
		* 
		* @param it The value for the node.
		*/
	public StackNode( Object it )
	{
		element = it;
		next = null;
	}	
  
  /**
	  * The constructor for this class. <p>
		* It initializes the fields element and next to the parameters given.
		* 
		* @param nextEle The reference to the next node.
		*/	
	public StackNode( StackNode nextEle )
	{
		next = nextEle;
	}
  
	/**
	  * Give the next node of the current node.
		* 
		* @return The reference of the next node.
		*/
  public StackNode next()
	{
		return next;
	}

	/**
	  * Set the next field of the current node to the parameter.
		*
		* @param nextEle The given node.
		* @return The set reference of the next node.
		*/
	public StackNode setNext( StackNode nextEle )
	{ 
		return next = nextEle;
	}

  /** 
	  * Give the value of the current node.
		* 
		* @return The value of the node.
		*/
	public Object element()
	{
		return element;
	}
  
	/** 
	  * Set the value of the current node.
		* 
		* @param it The value to be set.
		* @return The set value.
		*/
	public Object setElement( Object it )
	{
		return element = it;
	}	
}