Error 500

hi,

i need to run this code in a wordpress page. when i test it i always get the error 500 and in the page nothing is displayed.

<form action="http://www.derwandel.at/tools/machmit/gen.php" method="GET" target="_blank">

												<input type="radio" name="w" value="ich" />Ich bin Wandel
											<input type="radio" name="w" value="wir" /> Wir sind Wandel<br />
												<br />
												<input type="text" value="... weil"  name="statement" size="65" />
												<br />

												<br />
												<input type="radio" name="c" value="sw" />    S/W
											<input type="radio" name="c" value="farbe" /> Farbe<br />
												<br />
												<input type="submit" value="Go!" />
											</form>

any ideas what might be wrong?

thanks
conte

http://wordpress.org/extend/plugins/shortcode-exec-php/