if (document.images) {
    nav1on  = new Image(); nav1on.src  = "image/nav_home_down.gif";
    nav1off = new Image(); nav1off.src = "image/nav_home_up.gif";
    nav2on  = new Image(); nav2on.src  = "image/nav_samples_down.gif";
    nav2off = new Image(); nav2off.src = "image/nav_samples_up.gif";
    nav3on  = new Image(); nav3on.src  = "image/nav_about_down.gif";
    nav3off = new Image(); nav3off.src = "image/nav_about_up.gif";
    nav4on  = new Image(); nav4on.src  = "image/nav_contact_down.gif";
    nav4off = new Image(); nav4off.src = "image/nav_contact_up.gif";


}



function rollOn(img1,text){
    window.status = text;
    if (document.images) {
        document[img1].src=eval(img1 + "on.src");
    }
}

function rollOff(img1){
    window.status = "";
    if (document.images) {
		document[img1].src=eval(img1 + "off.src");
    }
}





function doPreload()
{

   var the_images = new Array('image/nav_samples_down.gif','image/nav_home_down.gif',
   'image/nav_contact_down.gif', 'image/nav_about_down.gif');
   preloadImages(the_images);
}

function preloadImages(the_images_array) {

   for(var loop = 0; loop < the_images_array.length; loop++)
	
   {
 	var an_image = new Image();
	an_image.src = the_images_array[loop];
   }
}

 var win= null;
 function NewWindow(mypage,myname,w,h,scroll){
 var winl = (screen.width-w)/2;
 var wint = (screen.height-h)/2;
 var settings ='height='+h+',';
 settings +='width='+w+',';
 settings +='top='+wint+',';
 settings +='left='+winl+',';
 settings +='scrollbars='+scroll+',';
 settings +='resizable=no';
 win=window.open(mypage,myname,settings);
 if(parseInt(navigator.appVersion) >= 4){win.window.focus();}
 } 

function MM_openBrWindow(theURL,winName,features) { 
 window.open(theURL,winName,features);
 }