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

function preloadImages() { 
    if(document.images){ 
	if(!document.preload_image_array) document.preload_image_array=new Array();
        var i;
	var number_of_images=document.preload_image_array.length;
	var args=preloadImages.arguments; 
        for(i=0; i<args.length; i++) {
            if (args[i].indexOf("#")!=0){ 
                document.preload_image_array[number_of_images]=new Image; 
               document.preload_image_array[number_of_images++].src=image_dir + args[i]; 
            } 
        }
    }
}

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

function randomTopImage() {
    if (default_banner == 0) {
       this_date = new Date();
       first_banner = Math.floor(this_date.getTime()/100000) % banner_list.length;
       document.write("<a href=\"#\" onClick=\"replaceTopImage();\"><img border=0 name=banner width=554 height=152 src=" + image_dir + "banners/" + banner_list[first_banner] + ".jpg></a>");
    } else {
       first_banner = default_banner;
       document.write("<a href=\"#\" onClick=\"replaceTopImage();\"><img border=0 name=banner width=554 height=152 src=" + image_dir + "banners/" + first_banner + ".jpg></a>");
    }
    current_image_num = first_banner;
}

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

function replaceTopImage() {
    image_num = Math.floor(Math.random()*1.0*banner_list.length); 
    while (image_num==current_image_num) {
	image_num = Math.floor(Math.random()*1.0*banner_list.length);   
    }
    document.images['banner'].src = image_dir + "banners/" + banner_list[image_num]+".jpg";
    current_image_num = image_num;
    if (replaceTopImage.arguments.length>0) { document.images['banner'].src = image_dir + replaceTopImage.arguments[0]+".jpg";}
}

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

function resetPage() { 
    writeDiv(story_content);		
    if (document.navbarform) {
    	key = document.navbarform.current_key.value;
        if (key != "") { 
          document.images['navbar-'+key].src = image_dir +"/navbar/" +key+ "-off.gif"; 
	}
    	document.images['infobar'].src = image_dir + "spacer.gif";
	setPageStateVariable('current_key','');
    }
}

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

function mouseOverNavBar(key) {
    if (document.navbarform) {
	current_key = document.navbarform.current_key.value;
    	if (key != current_key) { 
	    	document.images['infobar'].src=image_dir + "infobar/" + key +".gif";
		document.images['navbar-'+key].src = image_dir + "navbar/"+key+"-over.gif";
   	}
    }
}

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

function mouseOutNavBar(key) {
    if (document.navbarform) {
    	di = document.images;
    	di['navbar-'+key].src = image_dir + "navbar/"+key+"-off.gif";
    	current_key = document.navbarform.current_key.value;
    	if (current_key == '' || current_key==null || current_key =='null') { 
		di['infobar'].src=image_dir +"spacer.gif";
    	} else {
		di['navbar-'+current_key].src=image_dir +"navbar/"+current_key+"-on.gif";
		di['infobar'].src=image_dir +"infobar/" + current_key + ".gif";
    	}
    }
}

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

function clickOnNavBar(key,edit_section_id) {
   document.images['navbar-'+key].src = image_dir + "navbar/"+key+"-on.gif";
   writeSectionContent(edit_section_id);
   
   current_key = document.navbarform.current_key.value;
   setPageStateVariable('current_key',key);

   if ((current_key != '') && (current_key != 'null') && (current_key != key)) { 
	document.images['navbar-'+current_key].src= image_dir +"navbar/"+current_key+"-off.gif";
   }

}


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

function clickOnSearch(key) {
    ds = document.searchform;
    dss = ds.searchsite;
    di = document.images;
    di['search-'+dss.value+'-line'].src=image_dir +"search/vertical-bar.gif";
    di['search-'+dss.value].src=image_dir+"search/"+dss.value+"-off.gif";
    dss.value = key;
    di['search-'+key+'-line'].src=image_dir+"search/dimple.gif";
    di['search-'+key].src=image_dir +"search/"+key+"-on.gif";
    if (ds.searchtext.value != "") {submitSearch();}
}

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

function submitSearch() {
    document.searchform.submit();
}
//-------------------------------------------------------------

function mouseOverSearch(key) {
      dss = document.searchform.searchsite;
      di = document.images;
      if (dss.value != key) {
  	di['search-'+dss.value+'-line'].src=image_dir +"search/vertical-bar.gif";
	di['search-'+key+'-line'].src=image_dir+"search/dimple.gif";
        di['search-'+key].src=image_dir+"search/"+key+"-over.gif";
      }
}

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

function mouseOutSearch(key) {
    dss = document.searchform.searchsite;
    di = document.images;
    if (dss.value != key) {
	di['search-'+dss.value+'-line'].src=image_dir+"search/dimple.gif";
	di['search-'+key+'-line'].src=image_dir+"search/vertical-bar.gif";
	di['search-'+key].src=image_dir+"search/"+key+"-off.gif";
    }
}

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

function mouseGo(action) {
    document.images['search-go'].src=image_dir+"search/go-"+action+".gif";
}

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

function resetSearch() {
    dss = document.searchform.searchsite;
    di = document.images;
    search_list=["caltech", "directory", "calendar", "archives", "library"]
    for (i=0; i<search_list.length; i++) {
	di['search-'+search_list[i]+'-line'].src=image_dir+"search/vertical-bar.gif";
	di['search-'+search_list[i]].src=image_dir+"search/"+search_list[i]+"-off.gif";
    }
    di['search-'+dss.value+'-line'].src=image_dir+"search/dimple.gif";    
    di['search-'+dss.value].src=image_dir+"search/"+dss.value+"-on.gif";
}