Email attachments alert

I would like to put an alert on the emailing of documents where the flag to email an attachment is on 

 If a user has uploaded an attachment and wants to email it. 

 When we get to email and the user forgets to select the attachment he wants to send with the email. 

 An alert to come up to say 

 You have uploaded attachments to be sent with this email, but you have not selected the ones you want to send with this email 

 Continue without sending any attachments 

 Cancel to go and select attachments 

 Continue

 

 Cancel 

 If the user has selected the attachments, then you don’t need to pop up this message 

 This is to help the user remember that he attached documents to send with the email, but most times people forget to select them to email