function CheckUseremail(Obj,DOCDOMAIN){
    var useremail = $(Obj).val();
    if(useremail.length > 1){
        $.ajax({
            type: "post",
            url : DOCDOMAIN + "reg/check_useremail",
            dataType:'json',
            data: 'useremail=' + useremail,
            error: function(msg){
                return false;
            },
            success: function(json){
                if(json.flag == 2){
                    $(Obj).after('<label class="error" for="useremail" generated="true">email has been used.</label>');
                }
            }
        });
    }
}