// JavaScript Document

//	DECLARE VARIBLES 
var SS_main_img_id = "main_slide";	///	HTML ID of main image
var SS_array = new Array( "h1_tech.jpg", "h2_mmt.jpg", "h3_free.jpg", "h4_scan.jpg", "h5_caprese.jpg", "h6_risk.jpg" );
var SS_link_array = new Array( "eROI.php", "Affiliates.html", "Scanning.html", "Scanning.html", "eROI.php", "risk-assessment.html" );
var SS_num = SS_array.length;
var swapping_id = fade_away_id = fade_in_id = fade_in_delay_id = "clear";
if( navigator.appName == "Microsoft Internet Explorer" )
{
	var is_ie = true;
	var ie_op = 100;
}
else
{
	var is_ie = false;
}

function img_preload( img_array )
{
	var a = 0;
	while( a < img_array.length )
	{
		var temp_img = new Image();
		temp_img.src = "images/headlines/"+img_array[a];
		a++;
	}
}

function start_swapping()
{
	main_img = document.getElementById( SS_main_img_id );
	main_img.style.opacity = 1;
	img_counter = 0;
	swapping_id = setInterval( function() { go_swapping(); }, 6000 );
}
function go_swapping()
{
	if( is_ie )
	{
		fade_away_id = setInterval( function() { ie_fade_away(); }, 40 );
	}
	else
	{
		fade_away_id = setInterval( function() { fade_away(); }, 40 );
	}
}
function fade_away()
{		
	o_now = parseFloat( main_img.style.opacity ).toFixed(1);
	if( o_now > 0 )
	{
		main_img.style.opacity = o_now - 0.2;
	}
	else
	{
		clearInterval( fade_away_id );
		fade_away_id = "clear";
		next_img();
	}
}
function ie_fade_away()
{		
	if( ie_op > 0 )
	{
		ie_op = ie_op - 20;
		main_img.style.filter = "alpha(opacity="+( ie_op )+")";
	}
	else
	{
		clearInterval( fade_away_id );
		fade_away_id = "clear";
		next_img();
	}
}
function fade_in()
{
	clearTimeout( fade_delay_id );
	fade_delay_id = "clear";
	var o_now = parseFloat( main_img.style.opacity );
	if( o_now < 1.0 )
	{
		main_img.style.opacity = o_now + 0.2;
	}
	else
	{
		clearInterval( fade_in_id );
		fade_in_id = "clear";
	}
}
function ie_fade_in()
{
	clearTimeout( fade_delay_id );
	fade_delay_id = "clear";
	if( ie_op < 100 )
	{
		ie_op = ie_op + 20;
		main_img.style.filter = "alpha(opacity="+( ie_op )+")";
	}
	else
	{
		clearInterval( fade_in_id );
		fade_in_id = "clear";
	}
}

function next_img()
{
	img_counter++;
	if( img_counter >= SS_num )
	{
		img_counter = 0;
	}	
	var new_big = SS_array[ img_counter ];
	main_img.src = "images/headlines/"+new_big;
	switch_active_button( img_counter );
	
	//	"prefolder is for testing only	//

	var new_link = SS_link_array[ img_counter ];
	push_link ( "main_link", new_link );
	if( is_ie )
	{
		fade_delay_id = setTimeout( function() { fade_in_id = setInterval( function() { ie_fade_in(); }, 40 ) }, 200 );
	}
	else
	{
		fade_delay_id = setTimeout( function() { fade_in_id = setInterval( function() { fade_in(); }, 40 ) }, 200 );
	}
}
function do_list_div()
{
	document.write('<div id="SS_list"><ul>');
	for( var i = 0; i < SS_num; i++ )
	{
		document.write('<li onclick="jump_slide('+i+');" id="button'+i+'"');
		if( i == 0 )
		{
			document.write( 'class="current">'+(i+1)+'</li>' );
		}
		else
		{
			document.write( 'class="none">'+(i+1)+'</li>' );
		}
	}
	document.write('</ul></div>');
}
function jump_slide( slide_no )
{
	if( fade_away_id != "clear" || fade_in_id != "clear" || fade_in_delay_id != "clear" )
	{
		//	prevents function from continuing if previous run has not concluded
		return;
	}
	clearInterval( swapping_id );
	img_counter = parseInt( slide_no ) - 1;
	go_swapping();
	swapping_id = setInterval( function() { go_swapping(); }, 6000 );
}

function push_redirect( obj_id, target_link )
{
	var obj = document.getElementById( obj_id );
	//	when assigning a function to an object's event handler, 
	//	the function call cannot take arguements
	obj.onclick = new_redirect;
	
	function new_redirect( )
	{
		window.location.href = target_link;
	}
}

function push_link( a_id, target_link )
{
	var a = document.getElementById( a_id );
	a.href = target_link;
}
function switch_active_button ( button_no )
{
	var x = 0;
	while( x < SS_num )
	{
		if( x == button_no )
		{
			document.getElementById( "button"+x ).className = "current";
		}
		else
		{
			document.getElementById( "button"+x ).className = "none";
		}
		x++;
	}
}