Corrected misspelled word and corrected the way to display alert box

[guzzilar]

Hotfix PR Purpose

• Corrected misspelled word in page header
• Corrected the way to display alert box if error occur (in services/* folder)

...

Corrected misspelled word in page header

from @fred updated README.md in previous merged, It need to correct a misspelled in page header too

Corrected the way to display alert box if error occur (in services/* folder)

I missed some class for display alert box in the right way when service's error occur

Thanks

[fred]

:+1: