I am 20 and student and I work part-time in a medium-size company.
I don't have very specific job there. I am computer guy there and I do everything that somehow relates to computer there.
I don't have any problem with jobs assigned to me, but when I have to ask someone for his/her co-operation there comes the problem.
For example, one month ago I had to prepare some educational and advertising video clip about our industry for my company and I suggested one of our girls at office to my boss for doing narration on clip and he agreed. I asked her politely to do that. Doesn't work. I told her that I'm gonna be penalized if I don't finish clip in time. Doesn't work. Anytime I ask her to do the narration, she said that I'm tired, I don't have time and things like that. At last I penalized for the delay and then she narrated the clip the next day.
She is not evil and she doesn't have any problems with me. She didn't feel responsible for doing the job therefore she doesn't hurry to do the job quickly at time. That was for one month ago.
This month I am designing mugs for our office for each one of us with company logo at one side and each one's photo and name on the other side. I asked everyone to give me their photo with high quality just today. But I have the feeling that this job is going to be like the clip one and everyone doesn't care about their photo and don't give me photo at all or sending me their photos late or in best situation low quality photos.
Maybe it's because I am the youngest guy there they don't get me serious or maybe because I ask them too politely or etc.
What I am asking is how can I ask my co-workers for something that I am responsible for it?
Edit: Thanks for your answers. The thing everyone tells me is go to your boss and explain to him the situation. But my boss just told me that it's your own job and you should learn how to handle with your co-workers, how to ask people to do something it's important to you, you have to treat everyone the way they co-operate and things like that.
So maybe that's it. I have to learn how to manage negotiating my colleagues.
Edit 2: It worked! I had to prepare the photos until Thursday. But I told everyone you can only give your photos to me on Monday and on Monday night I send two images of flowers to anyone who haven't got me their photos yet and asked them which flower do you like on your mug. :) Tuesday was incredible. Each one of them gave me their high quality photo when I get to office as soon as they saw me.