// Global constants
var BB_URL = 'http://www.yahoo.com';
var DISPLAY_TIME=3500;
var TRANSITION_TIME=+0;

// Global variables
var primaryIdx=0;
var transIdx=0;

// First array contains primary images
JSBillboardArray = new Array( 2 );
JSBillboardArray[0] = new Image( 49, 333 );
JSBillboardArray[0].src = "images/Director's Column/Tim CD Pic 150 x 185 gainsboro.jpg";
JSBillboardArray[1] = new Image( 49, 333 );
JSBillboardArray[1].src = "images/Director's Column/tim sullivan family 150 x 185.jpg";

// Second array contains transitory images
transArray = new Array( 0 );
/*
transArray = new Array( 3 );
transArray[0] = new Image( 49, 333 );
transArray[0].src = "images/Gift_of_Life/gift_of_life_02103.jpg";
transArray[1] = new Image( 49, 333 );
transArray[1].src = "images/Gift_of_Life/gift_of_life_02168.jpg";
transArray[2] = new Image( 49, 333 );
transArray[2].src = "images/Gift_of_Life/gift_of_life_02171.jpg";

*/

function runJSBillboard()
{
	changeRate = DISPLAY_TIME + ( transArray.length * TRANSITION_TIME );
	setTimeout( "runJSBillboard()", changeRate );
	repaint();
}

function repaint()
{
	if ( transIdx > transArray.length -1 )
	{
		primaryIdx++;  // Increment primary image index
		transIdx = 0;  // reset transitonal image index
		if ( primaryIdx > JSBillboardArray.length -1 ) 
		{
			primaryIdx = 0;  // Reset primary index
		}
		document.billboard.src = JSBillboardArray[primaryIdx].src;
		return;  // Return to runJSBillboard()
	}
	 else
	{
		// Display transitional image
		document.billboard.src = transArray[transIdx].src;
		
		// Run repaint() recursively through cycle
		setTimeout( "repaint()", TRANSITION_TIME );
	}
	
	transIdx++;  // Increment transtionary index
}