// -----------------------------------------
// Copyright evenementendag-Nijkerkerveen.nl
// -----------------------------------------


//------------------------------------------
// Vervagen van achtergrond
//------------------------------------------
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 + ")";
}

//-------------------------------------------
//toggle the image sourch of an img tag
//-------------------------------------------
function toggle_image(id, first_image, second_image, milisec) {
	var img_obj = document.getElementById(id);
	var change_to_img = second_image;
	
	if(img_obj.src.lastIndexOf(second_image) != -1) {
		change_to_img = first_image;
	}

	if(milisec > 0) {
		opacity(id, 100, 0, parseInt(milisec/2));
		
		setTimeout("document.getElementById('"+id+"').src = '"+change_to_img+"'", parseInt(milisec/2));
		setTimeout("opacity('"+id+"', 0, 100, "+parseInt(milisec/2)+")", parseInt(milisec/2));

	} else {
		img_obj.src = change_to_img;
	}
}

//-------------------------------------------
// Foto boek
//-------------------------------------------
function show_big_image() {

}

function pre_tumbs() {
	var _tumbs = document.getElementById('tumbs');
	var imgs = _tumbs.getElementsByTagName('img');
	for (var i = 0; i < imgs.length; i++){              
		imgs[i].setAttribute('onclick', 'document.getElementById("big_image").innerHTML = "<img src=\''+imgs[i].src.replace('Mini', 'Grote')+'\' />"');        
	    //document.getElementById('big_image').innerHTML = imgs[i].src;
	}
}