function check_ack(oo){

	check = false;
	
	if(document.newsletter_form.email.value.search(/^[A-Za-z0-9.!#$%&'*+-/=?^_`{|}~]{2,}@[0-9A-Za-z][0-9A-Za-z-]{0,61}[0-9A-Za-z].[a-zA-z]{2,5}$/) != -1) check = true;//öäüÖÄÜß
	
	if(check == true){
	
		document.newsletter_form.email.style.border = "1px solid #79797b";
		
		if(oo == 0){
		
			if(document.newsletter_form.ack.checked == true){
			
				document.getElementById("inewsletter_register").style.color = "#FFFFFF";
				check = true;
			
			}else{
			
				document.getElementById("inewsletter_register").style.color = "#DD0000";
				check = false;
			
			}
		
		}else if(oo == 1) check = true;
	
	}else document.newsletter_form.email.style.border = "1px solid #AA0000";
	
	if(check == true) document.newsletter_form.submit();

}