function pop(url,w,h,s)
    {
        if(s == 1)
        {
            var scroll = 'yes';
        }
        else if(s == 0)
        {
            var scroll = 'no';
        }
        else
        {
            var scroll = 'yes';
        }
        window.open(url,'Grade','width='+w+',height='+h+',scrollbars='+scroll+'');
    }

function roll(img_name,img_src)
    {
        document[img_name].src = img_src;
    }

function show_hide(id)
	{
		if(document.getElementById(id).style.display == 'none') {
			return document.getElementById(id).style.display = 'block';
		} else if(document.getElementById(id).style.display == 'block') {
			return document.getElementById(id).style.display = 'none';
		}
	}
	
function show(id)
{
    return document.getElementById(id).style.display = 'block';
}

function hide(id)
{
    return document.getElementById(id).style.display = 'none';
}
	
function print_page()
    {
        var disp_setting="toolbar=yes,location=no,directories=no,menubar=yes,";
    	disp_setting+="scrollbars=yes,width=650, height=600, left=100, top=25";
    
    	var docprint = window.open("","",disp_setting);
    	docprint.document.open();
    	docprint.document.write('<html><head><title>Pagina titel</title>');
    	docprint.document.write('<link rel="stylesheet" href="http://www.grade.be/nl/print.css" type="text/css" />');
    	docprint.document.write('</head><body onload="self.print();">');
    	docprint.document.write(document.getElementById('print_content').innerHTML);
    	docprint.document.write('</body></html>');
    	docprint.document.close();
    	docprint.focus();
    }
  
function opacity(id, opacStart, opacEnd, millisec)
    {
        var speed = Math.round(millisec / 100);
        var timer = 0;
   
        if(opacStart > opacEnd) {
            for(i = opacStart; i >= opacEnd; i--) {
                setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
                timer++;
                setTimeout("document.getElementById('" + id + "').style.display = 'none'",1000);
            }
        } else if(opacStart < opacEnd) {
            for(i = opacStart; i <= opacEnd; i++)
                {
                document.getElementById(id).style.display = 'block';
                setTimeout("changeOpac(" + i + ",'" + id + "')",(timer * speed));
                timer++;
            }
        }
    }

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 nieuwsbrief() 
{
    URL = '../aanmelden_nieuwsbrief.php';
    day = new Date();
    id = day.getTime();
    eval("page" + id + " = window.open(URL, '" + id + "', 'toolbar=0,scrollbars=0,location=0,statusbar=0,menubar=0,resizable=0,width=400,height=100,left = 440,top = 412');");
}