I didn’t understand what should I change to make it work ?
Is that a question or a statement? Statements don’t end with question marks. You can’t expect us to know what you understand, so as a question, it doesn’t make sense.
Look at what you are passing to the emit_p() function. It is a string, with placeholders for data that emit_p() replace with the real data, and a list of values to substitute, in the order defined.
"<td><h3><center>Etat de la led: $S</center></h3><td> "
There’s a $S, where a string will be inserted.
"<center><a href=\"/?status=$S\"><input type=\"button\" value=\"$S\"></a></center/>"
There’s two more $S’s, where two more strings will be substituted.
"Analogue Pin A0.....$D
" // $D to put a value (number),$S to put text,$F to get flash contents
There’s a $D, where a numeric value will be substituted.
That’s a total of 4 placeholders, so you need to include 4 values in the list after the ) in this line:
), statusLabel, buttonLabel, buttonLabel);
But, you only have 3 values. You need to add 1 more, in the proper place in the list.