Gate for Garage door opening

[mz44]

I just built a 30x40 with 2 10x10 doors. I am looking for some kind of gate that I can put across the door openings that will keep the dog or kids out or in when the doors are up. I am thinking something about 3 ft high that will retract when not used. I recall seeing something at an industrial shop, accordian like metal that rolled out. Thanks

 

[honEXduner]

Something like this but maybe shorter?

http://www.uline.com/BL_3942/Folding-Security-Gates

 

[kbs2244]

Are you located near a good sized city?
What you are describing is a "door gate"
Very common in inner city industrial areas.
And now, very common on industrial surplus auction sites.