#purejs

function fadeOut(el_id, step)

{

var el = document.getElementById(el_id);

step = parseFloat(step);

var start_opacity = el.style.opacity || 1,

current_opacity = el.style.opacity || 1,

target_opacity = 0,

ie_val = 0;

var interval = setInterval(function() {

ie_val = (current_opacity * 100) - 5;

el.style.opacity = current_opacity;

el.style.filter = 'alpha(opacity=' + ie_val + ')';

current_opacity -= step;

if (current_opacity <= target_opacity)

{

clearInterval(interval);

el.style.opacity = target_opacity;

el.style.filter = 'alpha(opacity=' + (target_opacity * 100) + ')';

}

}, 1);

}

function fadeIn(el_id, step)

{

var el = document.getElementById(el_id);

step = parseFloat(step);

var start_opacity = parseInt(el.style.opacity, 10) || 0.1,

current_opacity = parseInt(el.style.opacity, 10) || 0.1,

target_opacity = 1,

ie_val = 0;

var interval3 = setInterval(function() {

ie_val = current_opacity * 100;

el.style.opacity = current_opacity;

el.style.filter = 'alpha(opacity=' + ie_val + ')';

current_opacity += step;

if (current_opacity >= target_opacity)

{

clearInterval(interval3);

el.style.opacity = target_opacity;

el.style.filter = 'alpha(opacity=' + (target_opacity * 100) + ')';

}

}, 1);

}

function switchFade(el1, el2)

{

fadeOut(el1, 0.001);

fadeIn(el2, 0.001);