seleccionar primer campo.

[davicito]

Hola, como puedo ahcer que automaticamente selecione el primer campo...

<form action="altaempresa.php" method="post" name="mayusculas">
<table>
<tr>
<td width="158"><div align="left"><strong>&nbsp;Nombre&nbsp;</strong></div></td>
<td width="268"><input onKeyUp="mayusculas.nombre_empresa.value=mayuscula s.nombre_empresa.value.toUpperCase();" type="text" name="nombre_empresa" size="33" maxlength="35"></td>
<td width="140" colspan="2" rowspan="11"><!--
<strong>&nbsp;Subir imagen:&nbsp;</strong>
<INPUT NAME="userfile" TYPE="file">-->
</td>
</tr><tr>
<td><div align="left"><strong>&nbsp;Dirección&nbsp;</strong></div></td>
<td><input type="text" name="direccion" size="33" maxlength="40"></td>
</tr><tr>
<td><div align="left"><strong>&nbsp;Población&nbsp;</strong></div></td>
<td><input type="text" name="poblacion" size="33" maxlength="20"></td>
</tr><tr>
<td><div align="left"><strong>&nbsp;Provincia&nbsp;</strong></div></td>
<td><input type="text" name="provincia" size="33" maxlength="20"></td>
</tr><tr>
<td><div align="left"><strong>&nbsp;C.P.&nbsp;</strong></div></td>
<td><input type="text" name="cpostal" size="33" maxlength="20"></td>
</tr><tr>
<td><div align="left"><strong>&nbsp;N.I.F.&nbsp;</strong></div></td>
<td><input type="text" name="nif" size="33" maxlength="20"></td>
</tr><tr>
<td><div align="left"><strong>&nbsp;E-mail&nbsp;</strong></div></td>
<td><input type="text" name="email" size="33" maxlength="45"></td>
</tr><tr>
<td><div align="left"><strong>&nbsp;Web&nbsp;</strong></div></td>
<td><input type="text" name="web" size="33" maxlength="45"></td>
</tr><tr>
<td><div align="left"><strong>&nbsp;Persona/s de Contacto&nbsp;</strong></div></td>
<td><input type="text" name="contacto" size="33" maxlength="20"></td>
</tr>
<tr>
<td><div align="left"><strong>&nbsp;Teléfono&nbsp;</strong></div></td>
<td><input type="text" name="telefono" size="33" maxlength="45"></td>
</tr><tr>
<td><div align="left"><strong>&nbsp;Mantenimiento&nbsp;</strong></div></td>
<td><input type="text" name="mantenimiento" size="33" maxlength="45"></td>
</tr><tr>
<td><div align="left"><strong>&nbsp;Notas&nbsp;</strong></div></td>
<td colspan="3"><textarea name="notas" cols="50" rows="10"></textarea></td>
</tr>
</table>
<br>
<input type="submit" value="Aceptar">
</form></center>