function sign_up(){
	email=document.getElementById("email").value;
	
	form=document.getElementById("main_form");
	form.action="http://lists.maddancermedia.com/cgi-bin/michaelcard/s.pl";
	
	if(isEmail(email)){
		win = window.open('','myWin','toolbars=0'); 
		form.target='myWin';
		form.submit();
	}
	else
		alert("Please Enter a Valid Email Address");
}

function isEmail(str) {
	var filter  = /^([a-zA-Z0-9_\.\-])+\@(([a-zA-Z0-9\-])+\.)+([a-zA-Z0-9]{2,4})+$/;
	return filter.test(str);
}