function sem(form){
 var okem=form.mail.value.match(/\b(^(\S+@).+((\.com)|(\.net)|(\.edu)|(\.mil)|(\.gov)|(\.org)|(\..{2,2}))$)\b/gi);
 if (okem){
 	form.submit();
 	}
 else{
 	alert("Upišite ispravnu email adresu.");
 	form.mail.focus();
 	form.mail.select();
 	}
 }