function toggle_visible_select(id,txt_show,txt_hide,img_show,img_hide) {
	
	if (document.getElementById(id).style.display == "block") {
		document.getElementById(id).style.display = "none";
		document.getElementById(id + '_hide_text').innerHTML = "<a href='Javascript:toggle_visible_select(\"" + id + "\",\""+txt_show+"\",\""+txt_hide+"\",\""+img_show+"\",\""+img_hide+"\");'>" + txt_show + "</a>";
		document.getElementById(id + '_arrow').innerHTML = "<a href='Javascript:toggle_visible_select(\"" + id + "\",\""+txt_show+"\",\""+txt_hide+"\",\""+img_show+"\",\""+img_hide+"\");'><img border=0 src='" + img_show + "'></a>";
	}
	else {
		document.getElementById(id).style.display = "block";
		document.getElementById(id + '_hide_text').innerHTML = "<a href='Javascript:toggle_visible_select(\"" + id + "\",\""+txt_show+"\",\""+txt_hide+"\",\""+img_show+"\",\""+img_hide+"\");'>" + txt_hide + "</a>";
		document.getElementById(id + '_arrow').innerHTML = "<a href='Javascript:toggle_visible_select(\"" + id + "\",\""+txt_show+"\",\""+txt_hide+"\",\""+img_show+"\",\""+img_hide+"\");'><img border=0 src='" + img_hide + "'></a>";
	}
		
		
	
}



function update_selection ()
{
	alert('update'); 
	
}

function checkSearch(message){
	
	if(document.getElementById('zoekveld').value == ''){
		alert(message);
		return false;
	} else {
		return true;
	}
	
}