                 constant:0)
             let layoutButtonBottom:NSLayoutConstraint = NSLayoutConstraint(
                 item:button,
-                attribute:NSLayoutAttribute.height,
+                attribute:NSLayoutAttribute.bottom,
                 relatedBy:NSLayoutRelation.equal,
                 toItem:background,
                 attribute:NSLayoutAttribute.bottom,

                multiplier:1,
                constant:0)
            let layoutButtonLeft:NSLayoutConstraint = NSLayoutConstraint(
                item:background,
                attribute:NSLayoutAttribute.left,
                relatedBy:NSLayoutRelation.equal,
                toItem:background,

                multiplier:1,
                constant:0)
            let layoutButtonRight:NSLayoutConstraint = NSLayoutConstraint(
                item:button,
                attribute:NSLayoutAttribute.right,
                relatedBy:NSLayoutRelation.equal,
                toItem:background,
                attribute:NSLayoutAttribute.right,
