forging of signature..

i am a nurse supervisor in a secondary hospital. i am handling an area so im in charge in creating the schedule for my area assigned. last week i had my vacation leave for about a week. ive created the schedule for the area but the final print out form was not yet available. when i came back from my vacation i was surprised that someone forged my signature on the schedule. what will i do? it was the 4th incident and im so clueless who did the forging. is it late for me to complain? im sure that my chief nurse is aware of the forging since she is the last person to sign the schedule. im not overreacting with this issue but the thing is, if that person was able to forge my signature on that simple document, then he/she can forge my signature on other important documents.

you can report this incident of forging with your human resource development department as this is part of the policy of code of conduct of the employees.