Q Extraño!
Prueba así:
Código HTML:
Ver original<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" lang="es"> .campo {
float : left;
text-align : right;
}
.line-through div{text-decoration: line-through;}
<script type="text/javascript"> function through(target) {
target.parentNode.parentNode.setAttribute("class", "line-through");
}
<tr><!-- Aquí aplico el estilo --> <td><div onclick="through(this);">campo1
</div></td>