<?php

if($_POST['ot'] == NULL AND $_POST['do'] == NULL){

$ot = 1;

$do = 100;

$set = '+';

}else{

$ot = abs(intval($_POST['ot']));

$do = abs(intval($_POST['do']));

$set = $_POST['set'];

}

if(isset($_POST['submit'])){

if($set == '+') $res = $ot+$do;

elseif($set == '-') $res = $ot-$do;

elseif($set == 'x') $res = $ot*$do;

elseif($set == ':') $res = $ot/$do;



$result = 'Результат: <b>'.$ot.' '.$set.' '.$do.' = '.$res.'</b><hr />';

}

echo '<div class="new"><form method="post">'.$result.'

Число 1:<br />

<input type="text" name="ot" value="'.$ot.'" /><br />

<select name="set">

<option value="+">+</option>

<option value="-">-</option>

<option value="x">x</option>

<option value=":">:</option>

</select><br />

Число 2:<br />

<input type="text" name="do" value="'.$do.'" /><br />

<input type="submit" name="submit" value="Получить" /> <input type="submit" name="refresh" value="Обновить" /></form></div>';



?>