/******************************************************************************
Copyright (C) Matteo Lucarelli - matteo@matteolucarelli.net

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
******************************************************************************/
// these are some cross-browser fade effect
// should work with all browsers exept konqueror and opera
// NOTE: to work with ie the id dimension must be specified

// set opacity of id from 0 (hide) to 100 (show)
function setOpacity(id, value)
{
	var elem = document.getElementById(id).style;
	elem.opacity = (value / 100);
	elem.MozOpacity = (value / 100);
	elem.KhtmlOpacity = (value / 100);
	//elem.setProperty("KhtmlOpacity","'"+value/100+"'");
	elem.filter = "alpha(opacity=" + value + ")";
}

// opacity loop from opacStart to opacEnd
// time base is 1/10 sec
function fadeLoop(id, opacStart, opacEnd, time) 
{
	var timer = 0;

	// switch between fade in and fade out
	if(opacStart > opacEnd) {
		for (i = opacStart; i >= opacEnd; i--) {
	        	setTimeout("setOpacity('" + id + "'," + i + ")",(timer * time));
			timer++;
		}
	} else if (opacStart < opacEnd) {
		for (i = opacStart; i <= opacEnd; i++) {
			setTimeout("setOpacity('" + id + "'," + i + ")",(timer * time));
			timer++;
		}
	}
}

// opacity loop from current val to opacEnd
// time base is 1/10 sec
// should be cross-broser after 1 setOpacity call
function fadeTo(id, opacEnd, time) 
{
	// default val is 100
	var opacCurr = 100;

	// retrive current opacity
	if(document.getElementById(id).style.opacity < 100) 
		opacCurr = document.getElementById(id).style.opacity * 100;

	fadeLoop(id, opacCurr, opacEnd, time);
}