function limite(zone,max)
{
	if(zone.value.length>=max)
	{
		zone.value=zone.value.substring(0,max);
	}
}

function is_mime_type(type,element)
{
	var types = (type=="cours")?  new Array("jpeg","jpg","jpe","pptm","pptx","ppt","xlsx","xls","docx","doc","pdf","odx","odt", 'odp', 'sxw', 'ods') : new Array("jpeg","jpg","jpe","tiff","tif","bmp","gif","fif","ras","mcf","wbmp");
	var file = element.value;
	var ext = file.substring(file.lastIndexOf(".")+1).toLowerCase();
	var egal=false;
	var i=0;
	while(!egal && i<types.length) {
		egal = (types[i]==ext);
		i++;
	}
	if(!egal)
	{
		alert("Le fichier n'est pas au format autorisé");
		var f = element ;
		var p = element.parentNode;
		p.removeChild(f);
		var i=document.createElement('input');
		i.setAttribute('id',element.id);
		i.setAttribute('type','file');
		i.setAttribute('name',element.name);
		i.setAttribute('size',element.size);
		(type=="cours")? i.setAttribute('onchange','is_mime_type("cours",this)') : i.setAttribute('onchange','is_mime_type("photos",this)');
		p.appendChild(i);
	}
}