diff --git a/Mantenimiento.php b/Mantenimiento.php
index d24792f..d618b77 100644
--- a/Mantenimiento.php
+++ b/Mantenimiento.php
@@ -358,7 +358,9 @@ class Mantenimiento {
                         }
                         $hayImagen = true;
                         $campoImagen = $campo;
-                    }                  
+                    } else {
+                        $valor = "null";
+                    }
                 } else {
                     $valor = $_POST[$campo] == "" ? "null" : '"' . $_POST[$campo] . '"';
                 }
diff --git a/plant/bootstrap.html b/plant/bootstrap.html
index bc696ec..f63e78e 100644
--- a/plant/bootstrap.html
+++ b/plant/bootstrap.html
@@ -58,7 +58,7 @@
                         {menu}
                     </ul>
                 </div>
-                <div class="col-sm-10 col-sm-offset-1 col-md-11 col-md-offset-1 main">
+                <div class="col-sm-10 col-sm-offset-2 col-md-11 col-md-offset-1 main">
                     <!--<h1 class="page-header">{opcion}</h1>-->
                     <!--<div id="divBarra" class="progress progress-striped active">
                         <div class="progress-bar" id="barra" role="progressbar" aria-valuenow="0" aria-valuemin="40" aria-valuemax="100" style="width: 0%">