How to delete all messages on facebook from iPhone?

I don't want to do it one at a time. Jeez I have typed alot of messages to one person and its a hassle deleting them one at a time -.-

I know how to delete messages on facebook from laptop and from iPhone its deleting one at a time.

Is there a way to delete all at once?

Please tell me step by step and thank you!

Click on see full conversation and then delete it.

1. Turn on your iPhone and tap the "SMS" icon on the main menu to launch the text inbox.

2. Select the unsent message that you want to remove from your phone and tap "Edit" on the top right corner.

3. Tap the radio button to select the outgoing message, then tap "Delete." The unsent message is deleted from your iPhone. Press the "Menu" button to go back to the main menu.

Select the unsent message that you want to remove from your phone and tap "Edit" on the top right corner.