// JavaScript Document

var fadeImages = new Array("pic1","pic2","pic3","pic4");

function doOpacity(id){
	for(x=0; x<fadeImages.length; x++){
		if(fadeImages[x] != id){
			if(document.getElementById(fadeImages[x]).style.opacity > 0){
				opacity(fadeImages[x], 100, 0, 500);
			}
		}
	}
	if(document.getElementById(id).style.opacity == undefined || document.getElementById(id).style.opacity < .99){
		opacity(id, 0, 100, 500);
	}
}

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 / 101);
    object.MozOpacity = (opacity / 101);
    object.KhtmlOpacity = (opacity / 100);
    object.filter = "alpha(opacity=" + opacity + ")";
}