function MM_swapImgRestore() { //v2.0
    if (document.MM_swapImgData != null)
	for (var i=0; i<(document.MM_swapImgData.length-1); i+=2)
	    document.MM_swapImgData[i].src = document.MM_swapImgData[i+1];
}

function MM_preloadImages() { //v2.0
    if (document.images) {
	var imgFiles = MM_preloadImages.arguments;
	if (document.preloadArray==null) document.preloadArray = new Array();
	var i = document.preloadArray.length;
	with (document) for (var j=0; j<imgFiles.length; j++) if (imgFiles[j].charAt(0)!="#"){
		preloadArray[i] = new Image;
		preloadArray[i++].src = imgFiles[j];
	    }
    }
}

function MM_swapImage() { //v2.0
    var i,j=0,objStr,obj,swapArray=new Array,oldArray=document.MM_swapImgData;
    for (i=0; i < (MM_swapImage.arguments.length-2); i+=3) {
	objStr = MM_swapImage.arguments[(navigator.appName == 'Netscape')?i:i+1];
	if ((objStr.indexOf('document.layers[')==0 && document.layers==null) ||
        (objStr.indexOf('document.all[')   ==0 && document.all   ==null))
	    objStr = 'document'+objStr.substring(objStr.lastIndexOf('.'),objStr.length);
	obj = eval(objStr);
	if (obj != null) {
	    swapArray[j++] = obj;
	    swapArray[j++] = (oldArray==null || oldArray[j-1]!=obj)?obj.src:oldArray[j];
	    obj.src = MM_swapImage.arguments[i+2];
	}
    }
    document.MM_swapImgData = swapArray; //used for restore
}

window.onload = function() {
    var randomImages = ["pics/banner_heli.jpg",
			"pics/banner_CD.jpg",
			"pics/banner_gears.jpg",
			"pics/banner_spring.jpg"];

    document.images['random_image'].src = randomImages[Math.floor(Math.random() * randomImages.length)];
};