function open_image(imgUrl,imgWidth,imgHeight)
{
   winTop=(screen.height-imgHeight)/2;
   winLeft=(screen.width-imgWidth)/2;
   if(imgHeight > screen.height) imgHeight = screen.height;
   if(imgWidth > screen.width) imgWidth = screen.width;
   window.open(imgUrl,"new_image","menubar=0,toolbar=0,top="+winTop+",left="+winLeft+",width="+imgWidth+",height="+imgHeight+",scrollbars=1");
}

function check_mail(mail)
{
	var reg = /^[a-zA-Z0-9][a-zA-Z0-9\._-]+@[a-zA-Z0-9_\.-]+\.[a-zA-Z]{2,4}$/;
	if(mail.value == '') return true;
	else return reg.test(mail.value);
} 

function ajax(div,url,pars,meth)
{
	if(!meth) meth = "get";
	var myAjax = new Ajax.Updater(div, "/"+url, {method: meth, parameters: pars});
}