Thanks for your readiness to share.
In an ideal world, JavaScript-driven links should only show up if the user has got JavaScript enabled (people who don't know that there is a back-button in their browser probably won't know how to enable JavaScript). So, I'd do that with a document.write. Additionally, using the HTML font-tag is not recommended, as it will render your entire page invalid. CSS-styling should be applied instead.
Full set of instructions:
1) Edit themes/yourtheme/theme.php, find$template_cpg_die =
and edit as suggested below. If you can't find that piece of code in your custom theme, copy// HTML template used by the cpg_die function
$template_cpg_die = <<<EOT
<tr>
<td class="tableb" align="center">
<font size="3"><b>{MESSAGE}</b></font>
<!-- BEGIN file_line -->
<br />
<br />
{FILE_TXT}{FILE} - {LINE_TXT}{LINE}
<!-- END file_line -->
<!-- BEGIN output_buffer -->
<br />
<br />
<div align="left">
{OUTPUT_BUFFER}
</div>
<!-- END output_buffer -->
<br /><br />
</td>
</tr>
EOT;
from themes/sample/theme.php into a new line before ?>
of the file themes/yourtheme/theme.php
2) In the variable definition that you pasted into your custom theme in step 1, find<!-- END output_buffer -->
<br /><br />
and add after it into a new line<script type="text/javascript">
document.write('<span style="font-weight:bold;color:red;font-variant:small-caps;">Click <a href="#" onclick="history.go(-1);return false;">here</a> to go back and try again (or use the back button on your browser).</span>');
</script>
3) Save your changes and upload your custom theme file to your webserver.
Sadly, this will be with hard-coded language - a true internationalization would be much more complicated and would require editing core files.