last commit implementation didn't even work properly but now it works

app/routes/threads/$threadId.jsx

@@ -12,7 +12,7 @@ export async function action({ request, params }) {
   const clonedData = request.clone();
   const formData = await clonedData.formData();
   const post = formData.get("post");
-  let replying = formData.get("replying");
+  const replying = formData.get("replying");
 
   const fileUploadHandler = unstable_createFileUploadHandler({
     directory: './public/uploads/',
@@ -41,18 +41,23 @@ export async function action({ request, params }) {
     errors.post = "Post too long or short";
   };
 
-  const currentThread = await prisma.thread.findUnique({
-    where: {
-      id: parseInt(threadId),
-    },
-    include: {
-      posts: true
-    },
-  });
+  if (replying !== "") {
+    let currentThreadreplyids = [];
+    const currentThread = await prisma.thread.findUnique({
+      where: {
+        id: parseInt(threadId),
+      },
+      include: {
+        posts: true
+      },
+    });
+    currentThread.posts.map(post => currentThreadreplyids.push(post.id));
 
-  if (typeof replying !== "string" || !parseInt(replying) || parseInt(replying) > currentThread.posts.length ) {
-    replying = ""
+    if (typeof replying !== "string" || !parseInt(replying) || !currentThreadreplyids.includes(parseInt(replying))) {
+      errors.replying = "bad reply id"
+    };
   };
+
   if (Object.keys(errors).length) {
     return json(errors, { status: 422 });
   };
@@ -66,7 +71,7 @@ export async function action({ request, params }) {
     },
   });
 
-  return redirect(`/threads/${threadId}#${createPost.id}`);
+  return redirect(`/threads/${threadId}`);
 };
 
 export async function loader({ params }) {
@@ -101,7 +106,7 @@ export default function Thread() {
   return (
     <Overlay>
       <div className="flex flex-col p-12 bg-ctp-crust border outline rounded shadow-ctp-green shadow-lg">
-        <div className="bg-ctp-base rounded p-4">
+        <div id="OP" className="bg-ctp-base rounded p-4">
           <span><strong>{data.title}</strong> Post id: <strong>{data.id}</strong> Created at: <strong>{new Date(data.createdAt).toLocaleString()}</strong> Reply count: <strong>{data.posts.length}</strong></span>
           <br />
           <div className="flex flex-col">