€ naar ƒ naar €

<?php
	$euro_veld = null;
	$gulden_veld = null;
	
	$euro_toelichting = null;
	$gulden_toelichting = null;
	
	if ( !empty ( $_GET [ 'euro' ] ) )
	{
		$_GET [ 'euro' ] = str_replace ( ',' , '.' , $_GET [ 'euro' ] );
		$euro_veld = $_GET [ 'euro' ];
		$float = floatval ( $_GET [ 'euro' ] );
		if ( $float != $_GET [ 'euro' ] )
			$euro_toelichting = 'Klopt niet. ';
		else
			$euro_toelichting = $float . ' euro is ' . $_GET [ 'euro' ] * 2.20371 . ' gulden';
	}
	
	if ( !empty ( $_GET [ 'gulden' ] ) )
	{
		$_GET [ 'gulden' ] = str_replace ( ',' , '.' , $_GET [ 'gulden' ] );
		$gulden_veld = $_GET [ 'gulden' ];
		$float = floatval ( $_GET [ 'gulden' ] );
		if ( $float != $_GET [ 'gulden' ] )
			$gulden_toelichting = 'Klopt niet. ';
		else
			$gulden_toelichting = $float . ' gulden is ' . $_GET [ 'gulden' ] / 2.20371 . ' euro';
	}
?>
<form action="<?php echo $_SERVER [ 'PHP_SELF' ]; ?>" method="get">
	<p>
		<label for="euro">Euro's:</label>
		<input type="text" name="euro" value="<?php echo $euro_veld; ?>" id="euro" />
		<?php echo $euro_toelichting; ?>
	</p>
	<p>
		<label for="gulden">Guldens:</label>
		<input type="text" name="gulden" value="<?php echo $gulden_veld; ?>" id="gulden" />
		<?php echo $gulden_toelichting; ?>
	</p>
	<p>
		<input type="submit" value="Reken om!" />
	</p>
</form>