# How to display errors in Event Receivers?

I am trying to implement a custom logic during the checkout of an item of a list in SharePoint 2010.

For this reason I added an Event Receiver that ovverides the method ItemCheckedOut.

The idea is to block the possibility to checkout a file if its Approval Status is Pending.

This is the code:

Public Overrides Sub ItemCheckedOut(ByVal properties As SPItemEventProperties)

Try

Me.EventFiringEnabled = False

Dim item As SPListItem = properties.ListItem

If item.ModerationInformation.Status = SPModerationStatusType.Pending Then

properties.ErrorMessage = "The document is still 'Pending' and cannot be checked out."
properties.Cancel = True

End If

Catch ex As Exception

properties.ErrorMessage = String.Format("An error occurred during execution of ItemCheckedOut event: {0}.", ex.Message)
properties.Cancel = True

Finally

Me.EventFiringEnabled = True

End Try

End Sub


The code is executed correctly when a user try to checkout a file in "Pending" status, but no errors are displayed and checkout operation completes successfully.

Do you know how to solve?