// SCRIPT:   Random Banner Display
  // Filename: banRandomImageDisplay.js
  // Purpose:  manage the random choosing of an
  //           image for banner.
  //           Slide-show capability included.
  //           Intended for banner images, but
  //           could be customized for any image display.
  //           Duplicated from bgRandomImageDisplay.js
  //           to configure specifically for main page banners.
  //
  // Author:   Deborah Lee Soltesz, USGS, 10/2001

  // to allow "next/previous" buttons to work properly, all images in
  // set should be the same width and height
  //



    // array indices
    banFilename = 0 ;
    banWidth    = 1 ;
    banHeight   = 2 ;
    banComment  = 3 ;

    // customize: edit path
    banBaseURL = "/assets/banners/" ;

    // customize: list images to be used in the script
    banArr = new Array (
        new Array ("new_title_mars.jpg", "600", "104", "Mercury")
    ) ;
        //new Array ("mercury01_no_title.jpg", "600", "104", "Mercury")
    // rraub - Commented out because of the incorrect name for astro, so we just have one hardcoded. 
        //new Array ("earth01.jpg",   "600", "104", "Earth"),
        //new Array ("earth02.jpg",   "600", "104", "Earth"),
        //new Array ("earth03.jpg",   "600", "104", "Earth"),
        //new Array ("jupiter01.jpg", "600", "104", "Jupiter"),
        //new Array ("mars01.jpg",    "600", "104", "Mars"),
        //new Array ("mercury01.jpg", "600", "104", "Mercury"),
        //new Array ("moon01.jpg",    "600", "104", "The Earth's Moon"),
        //new Array ("neptune01.jpg", "600", "104", "Neptune"),
        //new Array ("neptune02.jpg", "600", "104", "Neptune"),
        //new Array ("saturn01.jpg",  "600", "104", "Saturn"),
        //new Array ("saturn02.jpg",  "600", "104", "Saturn"),
        //new Array ("solar01.jpg",   "600", "104", "Solar"),
        //new Array ("uranus01.jpg",  "600", "104", "Uranus"),
        //new Array ("uranus02.jpg",  "600", "104", "Uranus"),
        //new Array ("venus01.jpg",   "600", "104", "Venus")
    numbanImages = banArr.length ;

    randomNum = Math.floor(Math.random() * numbanImages) ;

    // writes the image width
    function writeBanWidth () {
      document.write(banArr[randomNum][banWidth]) ;
    }

    // writes the image height
    function writeBanHeight () {
      document.write(banArr[randomNum][banHeight]) ;
    }

    // write out the path and filename to the chosen image
    function writeBanPathAndFilename () {
      document.write(banBaseURL + banArr[randomNum][banFilename]) ;
    }

    // write out the chosen image's comment
    function writeBanComment () {
      document.write(banArr[randomNum][banComment]) ;
    }

    // display next image in list in image tag named 'imgName'
    function nextBanImage (imgName) {
      randomNum = (randomNum + 1) % numbanImages ;
      document.images[imgName].src = banBaseURL + banArr[randomNum][banFilename] ;
    }

    // display previous image in list in image tag named 'imgName'
    function prevBanImage (imgName) {
      randomNum = (randomNum + numbanImages - 1) % numbanImages ;
      document.images[imgName].src = banBaseURL + banArr[randomNum][banFilename] ;
    }

    // change specified image tag named 'imgName' to chosen image
    function pickBanImage (imgName) {
      document.images[imgName].src = banBaseURL + banArr[randomNum][banFilename] ;
    }