Is a canvas sukkah kosher if it blows in the wind? How can you secure the walls to make it kosher?
 
For more Sukkot learning: 
What Makes a Kosher Sukkah?
What if it Rains on Sukkot?
What do you Have to Eat in Your Sukkah?
Can you Use a Mat to Cover Your Sukkah?
How Big Does Your Sukkah Need to Be?
Why it's a Mitzvah to be Happy on Yom Tov