Hi, Enable Mozilla Firefox's Spell-Check tool. Make a right-click on the Status Update text field and select “Check Spelling” from the pop-out menu. You'll see a check mark beside this option when the Mozilla Firefox's Spell-Check tool is active.

Thank You.

I found an answer that is the complete opposite of what you want.

https://support.mozilla.org/en-US/questions/1022023

Basically you do Tools > Options (Edit > Preferences in Mac and Linux) Under the Advanced tab, check "Check my spelling as I type"

I cannot find a Status Update text field?

My Menu\Tools has no Options field!