derkenuke, muchas gracias ya he podido solucionar el problema
no he contestado antes porque hasta ahora no he conjseguido hacerlo funcionar, he tenido que modificar algunas cosas mas
Aqui dejo el codigo con las modificaciones que he echo para que funcione por si a alguien le interesa
Código HTML:
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<title>Documento sin título</title>
<script language="javascript" type="text/javascript">
function add(){
NewRow = document.getElementById("Form").insertRow(5);
NewRow.id=5;
NewCell=NewRow.insertCell(-1);
NewCell.innerHTML="<b>Especificar Genero</b>";
NewCell=NewRow.insertCell(-1);
NewCell.innerHTML="<input type=\"text\" name=\"Genero\" size=\"40\" maxlength=\"100\">";
}
function remove(){
var oTr = NewRow;
while(oTr.nodeName.toLowerCase()!='tr') {
oTr=oTr.parentNode;
}
var root = oTr.parentNode;
root.removeChild(oTr);
}
function check(value) {
if (value == 0) {
added = "yes";
add();
}
else {
if(added=="yes") remove();
}
}
</script>
</head>
<body>
<form method="post" action="modules.php?name=$module_name&par=AddingFilm">
<table width="100%" border="0" cellspacing="3" id="Form">
<tr><td nowrap><b>Titulo</b></td><td><input type="text" name="title" size="40" maxlength="100"></td></tr>
<tr><td nowrap><b>Imagen</b></td><td><input type="file" name="imagen" size="40" maxlength="255"></td></tr>
<tr><td nowrap><b>Link de descarga</b></td><td><input type="text" name="down_link" size="40" maxlength="255"></td></tr>
<tr><td nowrap><b>Codigo para ver Online</b></td><td><input type="text" name="online_link" size="40" maxlength="255"></td></tr>
<tr><td nowrap><b>Genero</b></td><td><select name="genre" onChange="check(this.value)"><option value="13">Acción</option><option value="14">Animación</option><option value="15">Aventuras</option><option value="26">Comedia</option><option value="20">Drama</option><option value="24">Ficcion</option><option value="25">Historico</option><option value="22">Policiaca</option><option value="23">Suspense</option><option value="21">Terror</option><option value="0">Otro</option></select></td></tr>
<tr><td nowrap><b>Subgenero</b></td><td><input type="text" name="subgenre" size="40" maxlength="100"></td></tr>
<tr><td nowrap><b>Fecha de estreno</b></td><td><input type="text" name="day" size="2" maxlength="2">
<input type="text" name="month" size="2" maxlength="2">
<input type="text" name="year" size="4" maxlength="4"> (dia/mes/año)</td></tr>
<tr><td nowrap><b>Duracion</b></td><td><input type="text" name="duracion" size="40" maxlength="50"></td></tr>
<tr><td nowrap><b>Link de informacion</b></td><td><input type="text" name="infolink" size="40" maxlength="255"></td></tr>
<tr><td nowrap><b>Otra Informacion</b></td><td><input type="text" name="otherinfo" size="40" maxlength="255"></td></tr>
<tr><td nowrap><b>Sinopsis</b></td><td><textarea name="sinopsis" cols="60" rows="10"></textarea></td></tr>
<tr><td nowrap><b>Estrellas</b></td><td><input type="text" name="starts" size="40" maxlength="255"></td></tr>
<tr><td> </td><td><input type="submit" name="submit" value="Agregar"></td></tr>
</table></form>
</body>
</html>
Saludos