error while including another view file

[eluser]Unknown[/eluser]

Hey guys. I have gotten this error for many days please help.

A PHP Error was encountered

Severity: Warning

Message: require_once(header.php) [function.require-once]: failed to open stream: No such file or directory

Filename: libraries/Loader.php(673) : eval()'d code
here is my code for view_form.php
Line Number:
<tr>
<td><font size:"10" color=red>*</font>Vehicle No:</td>
<td>&lt;input type="text" name="vehicle" id="vehicle" placeholder="Enter vehicle no" size="25" class="php_input"&gt;&lt;/td></tr>
<tr><td>&nbsp;</td></tr>

<tr><td><font size:"10" color=red>*</font>Registration Place:</td>
<td>&lt;input type="text" name="regpl" id="regpl" placeholder="Enter Place or City name" size="25" class="php_input"&gt;&lt;/td>
</tr> <tr><td>&nbsp;</td></tr>
<tr>
<td><font size:"10" color=red>*</font>Registration Place:</td>
<td>&lt;?php include "date.php";?&gt;</td>
</tr>
<tr><td>&nbsp;</td></tr>