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 fadeIn(id) {
	makeVisible(id);
	opacity(id, 0, 100, 500);
}

function fadeOut(id) {
	opacity(id, 100, 0, 500);
	makeHidden(id);
}

function show(id) {
	makeVisible(id);
	opacity(id, 0, 100, 10);
}

function hide(id) {
	opacity(id, 100, 0, 10);
	makeHidden(id);
}

function makeVisible(id) {
	  var obj = document.getElementById(id);
	  obj.style.display = "block";
}

function makeHidden(id) {
	  var obj = document.getElementById(id);
	  obj.style.display = "none";
}