单击按钮时，如何发送包含表单中包含的数据的电子邮件？

So I simply need to collect the information from a HTML form I made and send it via an email. How can I achieve this? Do I need PHP or some stuff like that? What should I put in the HTML code?

$(function() {
/*
number of fieldsets
*/
var fieldsetCount = $('#formElem').children().length;

/*
current position of fieldset / navigation link
*/
var current     = 1;

/*
sum and save the widths of each one of the fieldsets
set the final sum as the total width of the steps element
*/
var stepsWidth  = 0;
var widths      = new Array();
$('#steps .step').each(function(i){
    var $step       = $(this);
    widths[i]       = stepsWidth;
    stepsWidth      += $step.width();
});
$('#steps').width(stepsWidth);

/*
to avoid problems in IE, focus the first input of the form
*/
$('#formElem').children(':first').find(':input:first').focus(); 

/*
show the navigation bar
*/
$('#navigation').show();

/*
when clicking on a navigation link 
the form slides to the corresponding fieldset
*/
$('#navigation a').bind('click',function(e){
    var $this   = $(this);
    var prev    = current;
    $this.closest('ul').find('li').removeClass('selected');
    $this.parent().addClass('selected');
    /*
    we store the position of the link
    in the current variable 
    */
    current = $this.parent().index() + 1;
    /*
    animate / slide to the next or to the corresponding
    fieldset. The order of the links in the navigation
    is the order of the fieldsets.
    Also, after sliding, we trigger the focus on the first 
    input element of the new fieldset
    If we clicked on the last link (confirmation), then we validate
    all the fieldsets, otherwise we validate the previous one
    before the form slided
    */
    $('#steps').stop().animate({
        marginLeft: '-' + widths[current-1] + 'px'
    },500,function(){
        if(current == fieldsetCount)
            validateSteps();
        else
            validateStep(prev);
        $('#formElem').children(':nth-child('+ parseInt(current) +')').find(':input:first').focus();    
    });
    e.preventDefault();
});

/*
clicking on the tab (on the last input of each fieldset), makes the form
slide to the next step
*/
$('#formElem > fieldset').each(function(){
    var $fieldset = $(this);
    $fieldset.children(':last').find(':input').keydown(function(e){
        if (e.which == 9){
            $('#navigation li:nth-child(' + (parseInt(current)+1) + ') a').click();
            /* force the blur for validation */
            $(this).blur();
            e.preventDefault();
        }
    });
});

/*
validates errors on all the fieldsets
records if the Form has errors in $('#formElem').data()
*/
function validateSteps(){
    var FormErrors = false;
    for(var i = 1; i < fieldsetCount; ++i){
        var error = validateStep(i);
        if(error == -1)
            FormErrors = true;
    }
    $('#formElem').data('errors',FormErrors);   
}

/*
validates one fieldset
and returns -1 if errors found, or 1 if not
*/
function validateSteps(){
    var FormErrors = false;
    for(var i = 1; i < fieldsetCount; ++i){
        var error = validateStep(i);
        if(error == -1)
            FormErrors = true;
    }
    $('#formElem').data('errors',FormErrors);
}

/*
validates one fieldset
and returns -1 if errors found, or 1 if not
*/

function validateStep(step){
    if(step == fieldsetCount) return;

    var error = 1;
    var hasError = false;
    $('#formElem').children(':nth-child('+ parseInt(step) +')').find(':input[required]:not(button)').each(function(){
        var $this       = $(this);
        var valueLength = jQuery.trim($this.val()).length;

        if(valueLength == '')
        {   

            hasError = true;
            $this.css('background-color','red');        
        }
        else
        {
            $this.css('background-color','yellow'); 
        }

    }


    );


    var $link = $('#navigation li:nth-child(' + parseInt(step) + ') a');
    $link.parent().find('.error,.checked').remove();

    var valclass = 'checked';

    if(hasError)
    {

        error = -1;
        valclass = 'error';
    }
    $('<span class="'+valclass+'"></span>').insertAfter($link);

    return error;
}


/*
if there are errors don't allow the user to submit
*/
$('#registerButton').bind('click',function(){
    if($('#formElem').data('errors')){
        alert('Please correct the errors in the Form');
        return false;
    }   
});

I took this .PHP file from a website:

    <?php
if(isset($_POST['email'])) {

// Debes editar las próximas dos líneas de código de acuerdo con tus preferencias
$email_to = "my.email@email.com";
$email_subject = "Contacto desde el sitio web";

// Aquí se deberían validar los datos ingresados por el usuario
if(!isset($_POST['first_name']) ||
!isset($_POST['last_name']) ||
!isset($_POST['email']) ||
!isset($_POST['telephone']) ||
!isset($_POST['comments'])) {

echo "<b>Ocurrió un error y el formulario no ha sido enviado. </b><br />";
echo "Por favor, vuelva atrás y verifique la información ingresada<br />";
die();
}

$email_message = "Detalles del formulario de contacto:

";
$email_message .= "Nombre: " . $_POST['first_name'] . "
";
$email_message .= "Apellido: " . $_POST['last_name'] . "
";
$email_message .= "E-mail: " . $_POST['email'] . "
";
$email_message .= "Teléfono: " . $_POST['telephone'] . "
";
$email_message .= "Comentarios: " . $_POST['comments'] . "

";


// Ahora se envía el e-mail usando la función mail() de PHP
$headers = 'From: '.$email_from."
".
'Reply-To: '.$email_from."
" .
'X-Mailer: PHP/' . phpversion();
@mail($email_to, $email_subject, $email_message, $headers);

echo "¡El formulario se ha enviado con éxito!";
}
?>

How can I implement it that when clicking the "Register" button it sends the email. I know that I need to change some stuff there but how can I connect them?