window.onload = initBannerLink;



var adImages = new Array("../../images/ridematchAd4a.jpg","../../images/ms_advertise_ad2.jpg","../../images/calculator-ad2.gif","../../images/cc_polarbear.jpg");

var adURL = new Array("alt_transportation/Ridematch.shtml","marguerite/BusAdvertising.shtml","alt_transportation/calculator.shtml","alt_transportation/Commute_Club.shtml");



//construct an array of image captions

var altArray = new Array( 

"Share the commute to Stanford: Try our free Ridematching Service",

"Advertise in the Marguerite Shuttle",

"Commute cost and carbon emissions calculator: Find out the costs of your solo commute",

"Join the Commute Club");





function rotate() {



//pick a random ad index to start the loop

var thisAd =  Math.round(Math.random()*3);//returns integer from 0 to 3



	document.getElementById("adBanner").src = adImages[thisAd];

	document.getElementById("adBanner").alt = altArray[thisAd];

	if (document.getElementById("adBanner").parentNode.tagName == "A") {

		document.getElementById("adBanner").parentNode.href = "http://transportation.stanford.edu/" + adURL[thisAd];

	}



}



function initBannerLink() {

	

	rotate();

}

//---------------









function changepix(){

  //Generate a random number to select a URL in the array:

	//randomNumb = Math.round(Math.random()*4)+1;//returns integer from 1 to 5

	randomNumb = Math.round(Math.random()*3)+1;//returns integer from 1 to 3

	quotesrc=quoteArray[randomNumb];

	altsrc=altArray[randomNumb];

	heightsrc=heightArray[randomNumb];

	hrefsrc=hrefArray[randomNumb];

	

  //write to the HTML page:

	document.open();

	document.write ( '<a href=\"' + hrefsrc + '\"><img src=\"images/'  + quotesrc + '\" alt=\"' + altsrc + '\" width=\"240\" height=\"' + heightsrc + '\" border=\"0\"></a>'  );

	document.close();

}