/* JavaScript Bible, Fourth Edition by Danny Goodman Publisher: John Wiley & Sons CopyRight 2001 ISBN: 0764533428 */
Image Object // global declaration for 'desk' images array var imageDB // pre-cache the 'desk' images if (document.images) { // list array index names for convenience var deskImages = new Array("desk1", "desk2", "desk3", "desk4") // build image array and pre-cache them imageDB = new Array(4) for (var i = 0; i < imageDB.length ; i++) { imageDB[deskImages[i]] = new Image(120,90) imageDB[deskImages[i]].src = deskImages[i] + ".gif" } } // change image of 'individual' image function loadIndividual(form) { if (document.images) { var gifName = form.individual.options[form.individual.selectedIndex].value document.thumbnail1.src = gifName + ".gif" } } // change image of 'cached' image function loadCached(form) { if (document.images) { var gifIndex = form.cached.options[form.cached.selectedIndex].value document.thumbnail2.src = imageDB[gifIndex].src } } // if switched on, cycle 'cached' image to next in queue function checkTimer() { if (document.images && document.Timer.timerBox.checked) { var gifIndex = document.selections.cached.selectedIndex if (++gifIndex > imageDB.length - 1) { gifIndex = 0 } document.selections.cached.selectedIndex = gifIndex loadCached(document.selections) var timeoutID = setTimeout("checkTimer()",5000) } } // reset form controls to defaults on unload function resetSelects() { for (var i = 0; i < document.forms.length; i++) { for (var j = 0; j < document.forms[i].elements.length; j++) { if (document.forms[i].elements[j].type == "select-one") { document.forms[i].elements[j].selectedIndex = 0 } } } } // get things rolling function init() { loadIndividual(document.selections) loadCached(document.selections) setTimeout("checkTimer()",5000) }