Require - Help For WARNING LETTER

Dear all,
Iam working in Retail sector,
Just i wanted to write Warning letter to Staff for below reasons
1) Arguing with Manager
2) Most of the time speaking in while working
3) Not listening to the manage,
Pls suggest how to mention above 3 points as a professionally

Dear Venugopalaswamy,
You can modify the following suitably.
To
.................................
" Certain undesirable behaviour has been brought to our notice.
These are not part of good conduct as per our company policy/ standing orders
Disobeying and arguing with Manager.
Unnecessary talking while working.
Not carrying out Manager's instructions.
You are hereby warned not to indulge in above activities,
failing which suitable disciplinary action will be taken against you".
Please consider and suitably modify to meet your requirement.
V.Raghunathan