[HTML] pobierz, plaintext 
<form action="index.php" method="post">
<table>
<tr>
<td>podaj liczbę</td>
<td><input name="liczba" type="text" /></td>
</tr>
 
[HTML] pobierz, plaintext 

[HTML] pobierz, plaintext 
form{
text-align:center;
}
[HTML] pobierz, plaintext 

[CSS] pobierz, plaintext 
display: block;
width: 80%;
margin: 0 auto;
[CSS] pobierz, plaintext