I need some coding help

I have two small jobs I think. I want to use imagemagick instead of GD on a thumbnail script. I have imagemagick on the server. I want to fix the the text on a page. The person who coded it for me used the str( function. The problem is it cuts off the words. PM for sites. <tr> <td height="122" align="left" valign="top"> <p style="margin:5px;" class="normal_black"><?php echo substr($offer_add , 0 , 400); ?></p></td> </tr> <tr> <td colspan="2" align="left" class="normal_black"><p style="margin:5px;" class="normal_black"><?php echo substr($offer_add , 400 , 4000); ?></p></td> </tr>