I'm trying to hide a Row when the screen is large and show it when the screen is small. Likewise I want to show a Row when the screen is large and hide it when the screen is small.

This works as intended in a html page. However, when I move it to Visual Studio (aspx page) it doesn't work. I've tried it with both a Master Page and without with no joy.

A sample of what I'm trying to accomplish is at this link:
http://www.billingsbestcleaningjobs.com/Blank.aspx

Any help would be much appreciated.