///////////////////////////////////////////////////////////////////////////////
//  Name      : ImageTraverse.js
//  Developer : S*Curve Technology Inc. 
//  Date      : Nov 2003
///////////////////////////////////////////////////////////////////////////////
var m_szImageItemMap = new Array();
var m_iCurrID			

// Main thread
function InitFirstImage(sParam)
{
    var sQueryVar
    	
	sQueryVar = getQueryVariable(sParam);
 			
	if (sQueryVar != "-1") {
	    m_iCurrID = Number(sQueryVar);
	}
	else {
	    m_iCurrID = 0;
    }
	
    SetImage();
    PreloadImages();
}
function SetImage()
{
	if ((m_iCurrID <= m_szImageItemMap.length-1) && (m_iCurrID >= 0)) 
	{
		document.images.ImagePlaceholder.src = "images/" + 
			m_szImageItemMap[m_iCurrID];
	}		
}
function getQueryVariable(variable) 
{ 
	// Get the query string
	var query = window.location.search.substring(1);
	
	// Break the query string into chunks
	var vars = query.split("&");  
		
	// return 
	for (var i=0;i<vars.length;i++) 
	{
   		var pair = vars[i].split("=");
		if (pair[0] == variable) 
		{
    		return pair[1];
		}
	} 
	alert('Query Variable ' + variable + ' not found');
	return ("-1");
}					
// Previous
function PrevClick()
{
	if (m_iCurrID > 0)
	{
		m_iCurrID = m_iCurrID-1;
	}
	else if (m_iCurrID == 0)
	{
    	m_iCurrID = m_szImageItemMap.length-1;
	}
	SetImage();
	PreloadImages();
}
function NextClick()
{
	if (m_iCurrID < m_szImageItemMap.length-1)
	{
		m_iCurrID = m_iCurrID + 1;	
	}
	else if (m_iCurrID == m_szImageItemMap.length-1) 
	{
		m_iCurrID = 0;
	}	
	SetImage();
	PreloadImages();
}				
function PreloadImages()
{
	var oImage1
	var oImage2
	
    // If currently not on the first or the last image
	if ((m_iCurrID > 0) && (m_iCurrID < m_szImageItemMap.length-1))
	{      
		oImage1 = new Image();
		oImage2 = new Image();
		oImage1.src = "images/" + m_szImageItemMap[m_iCurrID-1];
		oImage2.src = "images/" + m_szImageItemMap[m_iCurrID+1];
	}			
    // If currently on first image, init the next
	else if (m_iCurrID == 0)
	{
		oImage2 = new Image();				
		oImage2.src = "images/" + m_szImageItemMap[m_iCurrID+1];					
	}				
    // If currently on the last, init the first
	else if (m_iCurrID == m_szImageItemMap.length-1)
	{
		oImage1 = new Image();				
		oImage1.src = "images/" + m_szImageItemMap[0];				
	}
 }