This is with reference to the (name of the cause) we are organizing at (name of your organization) to (collect money/clothes/ etc.) for the (particular purpose).
We have been associated with the (state the cause with which your organization is associated, e.g. Empowerment of Physically Challenged). The (money/clothes, etc.) collected would be utilized in the (particular program).
We request you to kindly make your contribution in the form of (a cheque drawn in favor of …) We look forward to the generosity of people like you to make a difference in our efforts to alleviate the (level of the underprivileged).