/*Event.observe(window, 'load', init_arrow);
function init_arrow() {
	if($('push_semaines').getWidth() > 240) {
		$('arrow_gauche').style.display = 'block'; 
		$('arrow_droite').style.display = 'block'; 
	}
}

$(document).ready(function() {
	if($('#push_semaines').getWidth() > 240) {
		$('#arrow_gauche').style.display = 'block'; 
		$('#arrow_droite').style.display = 'block'; 
	}					   
});*/

function deplacement(element, valeur) 
{
	element = $(element);
	gauche = parseFloat(element.style.left  || 0) + valeur;
	if ((gauche >= (230-element.getWidth())) && (gauche <= 0))
	{
		element.style.left = gauche + 'px';
	}
}