Disable inventary submit button if no inventary entries

src/inventary/CreateInventary.js

@@ -38,7 +38,7 @@ function CreateInventary() {
     };
   };
 
-  const disabled = !picks;
+  const disabled = picks.length == 0;
 
   const supplierOptions = [<option key=""></option>].concat(
     suppliers.map((s) => <option key={s.ID}>{s.name}</option>)
@@ -77,7 +77,7 @@ function CreateInventary() {
       <Form.Group as={Row}>
         <Col>
           <div className="text-right">
-            <Button type="submit" disabled={disabled}>
+            <Button variant="primary" type="submit" disabled={disabled}>
               Añadir entrada
             </Button>
           </div>