var counter=0;

function opacity(id, opacStart, opacEnd, millisec) {
    //speed for each frame
    var speed = Math.round(millisec / 100);
    var timer = 0;

    //determine the direction for the blending, if start and end are the same nothing happens
    if(opacStart > opacEnd) {
        for(i = opacStart; i >= opacEnd; i--) {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    } else if(opacStart < opacEnd) {
        for(i = opacStart; i <= opacEnd; i++)
            {
            setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
            timer++;
        }
    }
}

//change the opacity for different browsers
function changeOpac(opacity, id) {
    var object = document.getElementById(id).style;
    object.opacity = (opacity / 100);
    object.MozOpacity = (opacity / 100);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
} 

function runSlideShow(max)
{
	opacity( "slide_div", 100, 0, 500 );
	setTimeout( "changePic("+max+")", 550 );
	
}

function changePic(max)
{
	counter++;
	if( counter >= max )
		counter = 0;
	
	// try to pre-load the next image
	if( counter < (max - 1) && document.images )
	{	
		var nextImage = new Image();
		nextImage.src = slidefiles[counter+1];	
	}
			
	var newfile = slidefiles[counter];
	
	document.getElementById('slide_img').src = newfile;
	
	opacity( "slide_div", 0, 100, 500 );
	setTimeout( "runSlideShow("+max+")", 7000 );
}