En el script prueba esto:
Código:
<script LANGUAGE="javascript">
var capa
function cambio(idCapa){
capa=document.getElementById(idCapa);
if (capa.visibility == "hidden") {
capa.visibility ="visible" ;
}else{
capa.visibility = "hidden" ;
}
}
//-->
</script>
Y el HMTL asi:
Código:
<body>
<form name="busca" method="post" action="formulario.php?op=2">
<table width="80%" height="30" border="0" cellspacing="1">
<tr valign="top">
<td width="8%">Buscar</td>
<td width="25%"><input type="text" name="buscar" size="30" /></td>
<td width="5%"></td>
<td width="62%" ><select name="opcion" onchange="if(this.value ==3) cambio('tres');">
<option value="0"> </option>
<option value="1" >Nro. Contenedor</option>
<option value="2" >Nro. Documento</option>
<option value="3" >Fecha</option>
</select>
</td>
</tr>
</table>
<br/>
<div id="tres">
<table id="fecha" width="66%" border="0" cellspacing="0">
<tr>
<td width="9%"> Inicio </td>
<td width="36%"><input type="text" id="inicio" name="inicio"/>
<button id="buttoninicio" >...</button></td>
<td width="6%">Fin </td>
<td width="39%"><input type="text" id="fin" name="fin"/>
<button id="buttonfin" >...</button></td>
</tr>
</table>
</div>
<input type="submit" name="Button1" value="Ir" />
</body>
Ya me contaras
Un saludo