i need help with a start.command for my mc server

I tried all i could to make a start.command but my computer says i need permission to use it even tho i do have permission and i run on yosmite and i am so pissed and dont know what to do please help me
i wanna be able to start my server by opening 1 file and 1 file only without doing extra work

We need a lot more detail than this. What are you trying to do? What software are you using? What have you written? What error messages are you getting?