// JavaScript Document

var centerPics = new Array();
// First item is name of image. Second item is text of images tag "alt" parameter.
centerPics[0] = new Array ("center_content01.jpg", "the automobile and the 21 st. Century");
centerPics[1] = new Array ("index_image1.jpg", "Creating technologies of Los Angeles");
centerPics[2] = new Array ("image.jpg", "Los Angeles County Technology Week");


var picsI=0, picsAltDefault="Creating technologies of Los Angeles";
function imgShow(direct){
  var picsSRC, picsALT;
  switch(direct){
    case "next": picsI=(picsI<(centerPics.length-1))?++picsI:0; break;
    case "prev": picsI=(picsI<=0)?0:--picsI; break;
    default: picsI=0;
    }
  if (picsI<=0) 
    window.document.getElementById("centimgP").style.visibility="hidden"; 
	else window.document.getElementById("centimgP").style.visibility="visible";
  if (picsI>=(centerPics.length-1))
    window.document.getElementById("centimgN").style.visibility="hidden"; 
	else window.document.getElementById("centimgN").style.visibility="visible";
  picsALT=(centerPics[picsI][1]==undefined || centerPics[picsI][1]=="")?picsAltDefault:centerPics[picsI][1];
  picsSRC=(centerPics[picsI][0]==undefined || centerPics[picsI][0]=="")?centerPics[0][0]:centerPics[picsI][0];
  window.document.getElementById("center_img").alt=picsALT;
  window.document.getElementById("center_img").src="/images/"+picsSRC;
}