Using WorldEdit to make the dome

[gazpacho146]

Ok. So, I'm making my own map, and I have no idea what to type in WorldEdit.. The guide says the diameter is 500, so I typed //hsphere glass 500 and I think the arena is WAY too big. Someone please help. I have no idea what I'm doing. What do I type in on Worldedit to get a dome with a diameter of 500?

 

[Aeruner]

//hsphere glass 500 makes a sphere with a diameter of 1000. Just change the 500 to 250.