1. If code won't execute first start with the error. It will tell you exactly what the problem is.
2. Just at a quick glance you are trying to set a label to a string. You want to set the .Text of the label2.
label2.Text = "The equivalent in feet is. " + result;
or you can do like this:
label2.Text = String.Format("The equivalent in feet is. {0}", result);