if (!(/^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,4})+$/.test(f.email.value))) { alert('Введите правильный е-mail!');f.email.select(); return false; }
javascript:alert( /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,4})+$/.test('_@_.__') ) // Выведет: true
javascript:alert( /^\w+([\.-]?\w+)*@\w+([\.-]?\w+)*(\.\w{2,4})+$/.test('abc--abc@yandex.ru') ) // Выведет: false
<form method='post' onSubmit = "return checkform(this); return isEmailCorrect(this,'email')"> E-mail:<input type='text' name='email' required>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>Untitled Document</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> </head> <body> <script language="javascript"> function isEmailCorrect(formname, fieldname) { var re = /^[a-zA-Z0-9\-_](([a-z0-9\-_\.\+\&]?)+[a-z0-9])?\@((\w([a-zA-Z0-9\-_]+\w)?\.[a-z]{2,4})|(([01]?\d\d|2[0-4]\d|25[0-5])\.([01]?\d\d|2[0-4]\d|25[0-5])\.([01]?\d\d |2[0-4]\d|25[0-5])\.([01]?\d\d|2[0-4]\d|25[0-5]))|(localhost))$/i; if(re.test(eval("document.forms['"+formname+"']."+fieldname+".value"))) return true; else { alert("Email incorrect!"); eval("document.forms['"+formname+"']."+fieldname+".focus()"); return false; } } </script> <form action="" name="contactForm" onsubmit="return isEmailCorrect('contactForm', 'email')"> Name: <input type="text" name="name"> Email: <input type="text" name="email"> <input type="submit" value="OK"> </form> </body> </html>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> <html> <head> <title>Untitled Document</title> <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1"> </head> <body> <script language="javascript"> function isEmailCorrect(formname, fieldname) { var re = /^[a-zA-Z0-9\-_](([a-z0-9\-_\.\+\&]?)+[a-z0-9])?\@((\w([a-zA-Z0-9\-_]+\w)?\.[a-z]{2,4})|(([01]?\d\d|2[0-4]\d|25[0-5])\.([01]?\d\d|2[0-4]\d|25[0-5])\.([01]?\d\d |2[0-4]\d|25[0-5])\.([01]?\d\d|2[0-4]\d|25[0-5]))|(localhost))$/i; if(re.test(eval("document.forms['"+formname+"']."+fieldname+".value"))) return true; else { alert("Email incorrect!"); eval("document.forms['"+formname+"']."+fieldname+".focus()"); return false; } } </script> <form action="" name="contactForm" > Name: <input type="text" name="name"> Email: <input type="text" name="email"> <input type="submit" value="OK"> </form> </body> </html>
onsubmit="return (isEmailCorrect('contactForm', 'email') && checkform(this))"