please correct this sentence

[jkl]

Would you plz correct it? THANKS

Hello F. D

This is to inform you all lights are out in study room 20M, on the second floor of main bulding.

Thank you.

j.

[Greg Forbes]

(Not a teacher)

This is to inform you (or Please be informed) THAT all lights are out in study room 20M, on the second floor of THE main building.

(The second part of the sentence would still be understood without the article "the," but grammatically its use is necessary).