Sustening or Sustaining: How To spell?

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

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