# Check-Items

This function is executed when clicking the "Check" button within the [Item Tab](/bom_window).\
All the [Items](/code_reference/commandlets/show-bomwindow/objects/item) from the BOM Window can be checked against ERP.

## Syntax

```powershell
Check-Items [-Items] <Item[]>
```

## Parameters

| Type                                                                 | Name  | Description                       | input/output | Mandatory | Default value |
|----------------------------------------------------------------------|-------|-----------------------------------|--------------|-----------|---------------|
| [Item](/code_reference/commandlets/show-bomwindow/objects/item) \[\] | Items | The Items which should be checked | input        | yes       |               |


## Return type

**void**

## Remarks

Each **unique** [Item](/code_reference/commandlets/show-bomwindow/objects/item) shown in the BOM Window will be passed to this function.

It's recommended to update the [](/bom_window/status) of all the Items with the [](/code_reference/commandlets/show-bomwindow/commandlets/update-bomwindowentity) cmdlet.

When an exception is thrown within this function, the BOM Window {ref}`shows the Exception <bom_window:errors>` message of the terminated Check operation.\
The [](/bom_window/status) of all the [Items](/code_reference/commandlets/show-bomwindow/objects/item) that where not updated, gets automatically changed to *Unknown*.

## Examples

**Marking all items that exist on ERP with Status and StatusDetails “Identical”, otherwise as “New”:**

```powershell
function Check-Items($items) {
     foreach($item in $items) {
        $erp_material = Get-ERPObject -EntitySet 'Materials' -Keys @{'Number' = $item._PartNumber} -Expand "Descriptions"
        if($erp_material) {
           $item | Update-BomWindowEntity -Status 'Identical' -StatusDetails 'Item exists in ERP'
         }else{
           $item | Update-BomWindowEntity -Status 'New' -StatusDetails 'Item does not exist in ERP'
         }
     }
}
```