diff --git a/app/Filament/Resources/RequestCharacteristicResource.php b/app/Filament/Resources/RequestCharacteristicResource.php
index b411bdc..a5d88d8 100644
--- a/app/Filament/Resources/RequestCharacteristicResource.php
+++ b/app/Filament/Resources/RequestCharacteristicResource.php
@@ -8,6 +8,7 @@ use App\Models\CharacteristicApproverMaster;
 use App\Models\Item;
 use App\Models\Machine;
 use App\Models\RequestCharacteristic;
+use Closure;
 use Filament\Facades\Filament;
 use Filament\Forms;
 use Filament\Forms\Components\Section;
@@ -21,6 +22,7 @@ use Filament\Tables\Actions\ImportAction;
 use Filament\Tables\Table;
 use Illuminate\Database\Eloquent\Builder;
 use Illuminate\Database\Eloquent\SoftDeletingScope;
+use Illuminate\Support\Facades\Schema;
 use Illuminate\Validation\Rule;
 
 class RequestCharacteristicResource extends Resource
@@ -236,7 +238,7 @@ class RequestCharacteristicResource extends Resource
                             })
                             ->required(),
                         // ->disabled(fn ($get) => self::isFieldDisabled($get))
-                        Section::make('Request Characteristic')
+                        Section::make('Request Characteristic Field')
                             // ->columnSpan(['default' => 2, 'sm' => 4])
                             ->reactive()
                             ->schema([
@@ -244,24 +246,82 @@ class RequestCharacteristicResource extends Resource
                                     ->label('Characteristic Name')
                                     ->reactive()
                                     ->afterStateUpdated(function ($state, callable $set, callable $get) {
+                                        $set('characteristic_name', strtoupper($state));
                                         $set('updated_by', Filament::auth()->user()?->name);
                                     })
                                     ->required()
-                                    ->disabled(fn ($get) => self::isFieldDisabled($get)),
+                                    ->rules([
+                                        // function (callable $get) {
+                                        //     return Rule::unique('request_characteristics', 'characteristic_name')
+                                        //         ->where('plant_id', $get('plant_id'))
+                                        //         ->where('machine_id', $get('machine_id'))
+                                        //         ->where('machine_name', $get('machine_name'))
+                                        //         ->ignore($get('id'));
+                                        // },
+                                        function (callable $get): Closure {
+                                            return function (string $attribute, $value, Closure $fail) use ($get) {
+                                                $charVal = strtolower($value);
+                                                $columns = Schema::getColumnListing('class_characteristics');
+
+                                                if (! in_array($charVal, $columns, true)) {
+                                                    $fail('Unknown characteristic field found.'); // .implode(', ', $columns).
+                                                } else {
+
+                                                    $plantId = $get('plant_id');
+                                                    $jobNo = $get('aufnr');
+                                                    $updId = $get('id');
+                                                    $pendingExists = RequestCharacteristic::where('plant_id', $plantId)->where('aufnr', $jobNo)->where('characteristic_name', $value)->latest()->first();
+
+                                                    if ($pendingExists) {
+                                                        if ($updId && $pendingExists->id == $updId) {
+                                                            return;
+                                                        }
+                                                        $app1 = $pendingExists->approver_status1 ?? null;
+                                                        $app2 = $pendingExists->approver_status2 ?? null;
+                                                        $app3 = $pendingExists->approver_status3 ?? null;
+
+                                                        if ($app1 != 'Rejected' && $app2 != 'Rejected' && $app3 != 'Rejected' && $app1 != 'Approved' && $app2 != 'Approved' && $app3 != 'Approved') {
+                                                            $fail('Approval is already pending.');
+                                                        }
+                                                    }
+                                                }
+                                            };
+                                        },
+                                    ])
+                                    ->readOnly(fn ($get) => self::isFieldDisabled($get)), // disabled
                                 Forms\Components\TextInput::make('current_value')
                                     ->label('Current Value')
                                     ->reactive()
                                     ->afterStateUpdated(function ($state, callable $set, callable $get) {
                                         $set('updated_by', Filament::auth()->user()?->name);
                                     })
-                                    ->disabled(fn ($get) => self::isFieldDisabled(get: $get)),
+                                    ->required(function (callable $get) {
+                                        $updateVal = $get('update_value');
+                                        if ($updateVal == null || $updateVal == '') {
+                                            return true;
+                                        }
+
+                                        return false;
+                                    })
+                                    ->readOnly(fn ($get) => self::isFieldDisabled($get)),
                                 Forms\Components\TextInput::make('update_value')
                                     ->label('Update Value')
                                     ->reactive()
                                     ->afterStateUpdated(function ($state, callable $set, callable $get) {
                                         $set('updated_by', Filament::auth()->user()?->name);
                                     })
-                                    ->disabled(fn ($get) => self::isFieldDisabled($get)),
+                                    ->rules([
+                                        function (callable $get): Closure {
+                                            return function (string $attribute, $value, Closure $fail) use ($get) {
+                                                $currVal = $get('current_value');
+
+                                                if ($value == $currVal) {
+                                                    $fail('Update value must be different from current value.');
+                                                }
+                                            };
+                                        },
+                                    ])
+                                    ->readOnly(fn ($get) => self::isFieldDisabled($get)),
                             ])
                             ->collapsible()
                             ->columns(['default' => 1, 'sm' => 3]),
@@ -798,6 +858,19 @@ class RequestCharacteristicResource extends Resource
                     ->dateTime()
                     ->searchable()
                     ->sortable(),
+                Tables\Columns\TextColumn::make('mail_status')
+                    ->label('Mail Status')
+                    ->alignCenter()
+                    ->searchable()
+                    ->sortable()
+                    ->toggleable(isToggledHiddenByDefault: true),
+                Tables\Columns\TextColumn::make('trigger_at')
+                    ->label('Trigger At')
+                    ->dateTime()
+                    ->alignCenter()
+                    ->searchable()
+                    ->sortable()
+                    ->toggleable(isToggledHiddenByDefault: true),
                 Tables\Columns\TextColumn::make('created_at')
                     ->label('Created At')
                     ->dateTime()