UNLINKING SYMBOLS INSTANCES

hI,

I would like to unlink all symbols instances used in a file.

I have tried something that does not work. The script does not unlink because I am stuck at this step.

#target illustrator

var doc=activeDocument;

UnlinkAll(doc);
function UnlinkAll(doc){
     var SLen=doc.symbols.length-1;
     for (si=SLen;si>-1;si--){
   alert(doc.symbolItems.getByName(doc.symbols[si])) ;

     return true;
     }
}

JPD