Outdoor Dryer How Do I Keep This Outdoor Dryer From Tipping Over?

How do I keep this outdoor dryer from tipping over? - outdoor dryer

I bought a 3-arm aluminum exterior drying rack at Wal-Mart. I now for the 1st Great time hanging curtains. It seems that there is today a light breeze, and I was always on my hair stand on end to get on the terrace. I've tried to fix a rope to the railing of the porch, which did not help too. Has anyone suggestions how to follow a safe procedure?