Hmmm

Yep, I'm stupid ... Sorry ... I forget to say I've done that too ... I've tried it after posting my precedent message ...
But in "Design view" ... ok, I can put anything on It from the tools bar, but how could I save what I've done ?
I put a label on the page (near the already existing button "click me").
How do I save it ? If I click on the code view, when I come back on the design view, the label is missing.
I've tried to click on the upper button "Save all changed files" near the open project button ... I doesn't change anything.
And another thing : If I put a button, for example, how change the "onclick" event ? When I click on the little icon a rigth of the event value, nothing happens !
And in the code view, If I want to put some code, It's impossible as I can't write anything in this page. And the menu "Instance" has no effect.
In fact, nothing is working ... except the possiblity to add numbers of tools in the tool box, but I can't wirte any code, I can't save anything, I can't write any event ...
I have the documentation, I've tried to follow it, but nothing is working as it's writen !
I don't understand ...
Sory for my stupidity.
KP.