Sustoning or Sustaining: How To spell?

The word Sustoning is misspelled against Sustaining, which is present continuous of "Sustain"

Word contains consecutive vowels 'AI' in between alphabets sust & ning is misspelled as 'O'
Wrong Spelling: sust-o-ning
Correct Spelling: sust-ai-ning
Check more misspelled words of Sustaining to spell it correct.