This week I assign my students to write a notice based on the following situation:
The Student Union is to organize an English Speech Contest. You are supposed to write a notice on behalf of the Student Union to inform all the students at your university to participate in it.
After collecting their writing, I found one of their common problems is that the content of the body is empty. So I go to the Internet, search the topic and write a notice on my own. I think that there are still some expressions or sentences which are not native English. So could you help me to correct the notice?

English Speech Contest
September 18
An English Speech Contest will be held at the university auditorium by the Student Union. Any of the full-time students is qualified to participate in it. Contestants will be divided into two categories: English majors and non-English majors.The Contest goes through two phases: the initial and the final. In the inital, contestants are free to choose topics, and oral English teachers will be invited to be judges . The top five contestants in each category will enter the final. In the final, each contestant will be allocated a topic, and the top three will be final winners who will be awared prizes by the principal of our college. If you are interested, please come to the English Speech Organizing Committee Office at Room 203 of Teaching Building II and decide speech orders by drawing lots on October 15 at 18:00. On October 25 at 18:00 begins the final. For more information, please call Mr. Zhang at 88413677-6203.
Student Union