[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?.)+(?:[A-Z]{2}|com|org|net|edu|gov|mil|biz|info|mobi|name|aero|asia|jobs|museum)

$j("#fld_emailaddress").live('change',function() {
var emailaddress = $j("#fld_emailaddress").val();

// validation here?

if(emailaddress){}

// end validation

$j.ajax({
        type: "POST",
         url: "../ff-admin/ff-register/ff-user-check.php",
        data: "fld_emailaddress="+ emailaddress,
        success: function(msg)
        {
            if(msg == 'OK') {
            $j("#fld_username").attr('disabled',false);
            $j("#fld_password").attr('disabled',false);
            $j("#cmd_register_submit").attr('disabled',false);
            $j("#fld_emailaddress").removeClass('object_error'); // if necessary
            $j("#fld_emailaddress").addClass("object_ok");
            $j('#email_ac').html('&nbsp;<img src="img/cool.png" align="absmiddle"> <font color="Green"> Your email <strong>'+ emailaddress+'</strong> is OK.</font>  ');
            } else {
            $j("#fld_username").attr('disabled',true);
            $j("#fld_password").attr('disabled',true);
            $j("#cmd_register_submit").attr('disabled',true);
            $j("#fld_emailaddress").removeClass('object_ok'); // if necessary
            $j("#fld_emailaddress").addClass("object_error");
            $j('#email_ac').html(msg);
            }
        }
     });
});

function isValidEmailAddress(emailAddress) {
    var pattern = /^([a-zd!#$%&'*+-/=?^_`{|}~u00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]+(.[a-zd!#$%&'*+-/=?^_`{|}~u00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]+)*|"((([ t]*rn)?[ t]+)?([x01-x08x0bx0cx0e-x1fx7fx21x23-x5bx5d-x7eu00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]|\[x01-x09x0bx0cx0d-x7fu00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]))*(([ t]*rn)?[ t]+)?")@(([a-zdu00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]|[a-zdu00A0-uD7FFuF900-uFDCFuFDF0-uFFEF][a-zd-._~u00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]*[a-zdu00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]).)+([a-zu00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]|[a-zu00A0-uD7FFuF900-uFDCFuFDF0-uFFEF][a-zd-._~u00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]*[a-zu00A0-uD7FFuF900-uFDCFuFDF0-uFFEF]).?$/i;
    return pattern.test(emailAddress);
};

if( !isValidEmailAddress( emailaddress ) ) { /* do stuff here */ }

function isValidEmailAddress(emailAddress) {
    var pattern = new RegExp(/^[+a-zA-Z0-9._-]+@[a-zA-Z0-9.-]+.[a-zA-Z]{2,4}$/i);
    // alert( pattern.test(emailAddress) );
    return pattern.test(emailAddress);
};

$(document).ready(function() {

$('#emailid').focusout(function(){

                $('#emailid').filter(function(){
                   var emil=$('#emailid').val();
              var emailReg = /^([w-.]+@([w-]+.)+[w-]{2,4})?$/;
            if( !emailReg.test( emil ) ) {
                alert('Please enter valid email');
                } else {
                alert('Thank you for your valid email');
                }
                })
            });
});

function isValidEmailAddress(emailAddress) {
        var pattern = new RegExp(/^([w-.]+@([w-]+.)+[w-]{2,4})?$/);
        return pattern.test(emailAddress);
    };

$("input#email-address").verimail({
    messageElement: "p#status-message"
});

if($("input#email-address").getVerimailStatus() < 0){
    // Invalid email
}else{
    // Valid email
}

var pattern = new RegExp("^[_A-Za-z0-9-]+(\.[_A-Za-z0-9-]+)*@[A-Za-z0-9]+(\.[A-Za-z0-9]+)*(\.[A-Za-z]{2,})$");
var result = pattern .test(str);

abc@gmail..com
abc@gmail.com..

abc.efg@gmail.com
abc@gmail.com.my

var emailRegex = new RegExp(/^([w.-]+)@([w-]+)((.(w){2,3})+)$/i);
 var valid = emailRegex.test(emailAddress);
  if (!valid) {
    alert("Invalid e-mail address");
    return false;
  } else
    return true;