demo: fixed typo and use px

demo/Button/MainUnit.lfm

@@ -24,7 +24,7 @@ object MainForm: TMainForm
         OnMouseDown = Label1MouseDown
         OnMouseMove = Label1MouseMove
         OnMouseUp = Label1MouseUp
-        Caption = 'Labgl1'
+        Caption = 'Label1'
       end
     end
   end

demo/ButtonGenerator/DemoButtonGenerator.pas

@@ -206,14 +206,14 @@ var
 begin
   if ButtonDiv=nil then exit;
   NewStyle:=
-     'font-size:'+FloatToCSSStr(FontSizeSlider.Position)+'px;'
-    +'padding: '+FloatToCSSStr(PaddingVerticalSlider.Position)+'px 31px;'
-    +'border-width:'+FloatToCSSStr(BorderWidthSlider.Position)+'px;';
+     'font-size:'+FloatToCSSPx(FontSizeSlider.Position)+';'
+    +'padding: '+FloatToCSSPx(PaddingVerticalSlider.Position)+' 31px;'
+    +'border-width:'+FloatToCSSPx(BorderWidthSlider.Position)+';';
 
   if GradientChkBox.Checked then
     NewStyle+='background-image:linear-gradient('+BackgroundColor1+','+BackgroundColor2+');';
 
-  Radius:=FloatToCSSStr(BorderRadiusSlider.Position)+'px';
+  Radius:=FloatToCSSPx(BorderRadiusSlider.Position);
   s:='';
   if BorderRadiusTopLeftChkBox.Checked then
     s:=Radius