Php snipest issue

Hi,
My site prevents me for administration after installing this code.

<?php
/**
* The following snippet displays the next 10 upcoming events
* in a scrolling box that is set in a simple DIV styled inline.
* To increase or decrease the number of events listed just change
* the $listlength value
*
* no javascript is required and the current
* height, width is 150 X 320 pixels.
* to increase decrease that simply change the values for
* the $boxheight and $boxwidth
*
* works with most popular browsers
* Tested in IE6, Mozilla Firefox 1.0 & 1.5, and NN7
*
* Tested and works with with Drupal 4.5.x and Drupal 4.6.x
*
*
*/
$listlength="15";
$boxheight="150px";
$boxwidth="320px";
print "<h1>Upcoming Events</h1><div style=\"unicode-bidi:bidi-override; direction:rtl; display:block; width:$boxwidth; height:$boxheight; overflow:auto; padding-left:10px; border:1px solid #ba8; \"><div dir=\"ltr\"><p>";
print  event_block_upcoming($limit=$listlength);
print "</p></div></div>";
?>

the snipest URL is http://drupal.org/node/23236
The message appear:- "Fatal error: Call to undefined function: event_block_upcoming() in /home/pranu98/public_html/Home/includes/common.inc(1150) : eval()'d code on line 28"
Now I am not able to go on my administration page.
What can I do? Please Help me.