clear pasteboard with alert (yes or no)

Hi All,

I am trying to clear pasteboard with yes or no alert, script running without error but not functioning

What my error, any help ?

//Pasteboard Clean
confirm("Do you want to Clean PasteBoard?");
if (confirm.window==true) function removePasteboardItems() {

removePasteboardItems(app.documents.length && app.activeDocument); 
function removePasteboardItems(/*?Document*/doc) {     if( !doc ) return;     var items = doc.pageItems.everyItem().getElements(),         t = null;     while( t=items.pop() ) t.parentPage || removeItem(t);     t = items = null; 
}
function removeItem(/*PageItem*/item) 
{     try {         item.locked = false;         item.remove();         }     catch(_){} 
} 
}else  {    exit();    }

Thanks in advance

Steve