Finding control in a web page

HI all.

I need to find in a web page the next input control after a ISSN text inside a td.

How can I do this?

<table id="ucModProductos1_tablaRetroalimentacion" width="100%" border="0"><tbody><tr class="TitulosCamposFormView" style="font-size:small;font-weight: bold"><td align="center">ISSN</td></tr><tr><td style="font-size:small"><input name="ucModProductos1$T_1091" type="text" maxlength="50" id="ucModProductos1_T_1091" </td></tr></tbody></table>

Thanks.