function changePreviewerToSize(selectedSize) {
    var leftPadding = new Array();
    var rightMargin = new Array();
    var mixbookPreviewerId = "mixbook_previewer";
    // changes the previewer to its corresponding size
    if (!(Element.hasClassName(mixbookPreviewerId,selectedSize+'_player'))) { // check to see if the same class
        var sizes = ["small","medium","large","xlarge"]; // remove whichever classes it has
        var paddingValues = [0,100,200,350]; // 10 is the default padding
        var i = 0;
        sizes.each(function(size) {
            leftPadding[size] = (10+paddingValues[i]).toString()+"px";
            rightMargin[size] = (paddingValues[i]).toString()+"px"; // there is already 10px of right padding
            i=i+1;
            if (Element.hasClassName(mixbookPreviewerId, size+'_player')) {
                Element.removeClassName(mixbookPreviewerId, size+'_player');
                Element.removeClassName(size+"_link", "selected");
            }
        });
        Element.addClassName(mixbookPreviewerId, selectedSize+'_player');
        Element.addClassName(selectedSize+"_link", "selected"); // bold the currently selected size
        $('page_container').style.paddingLeft = leftPadding[selectedSize];
        $('page_container').style.marginRight = rightMargin[selectedSize]; // need this to counterbalance the offset done by PaddingLeft
        window.scroll(0,125); // move down to show the book
    }

}
function showCommentForm () {
    Element.show('add_comment_form');
    $('comment_text').focus()
}
function fireInlineEvent(element,eventName){
    var target=$(element);
    if(target[eventName]==null){
        var attributeName='on'+eventName.toLowerCase();
        var attribute=target.attributes.getNamedItem(attributeName);
        if(attribute){
            target[eventName]=function(){
                eval(attribute.value);
            }
        }
    }
    if(target[eventName])target[eventName]();
}
function togglePanel(panel){
    if(isPanelExpanded(panel)){
        collapsePanel(panel);
    }
    else{
        expandPanel(panel);
    }
}
function collapsePanel(panel){
    if(isPanelExpanded(panel)){
        removeClass(panel,'expanded');
        fireInlineEvent(panel,'collapsed');
    }
}
function hasClass(element,_className){
    if(!element){
        return;
    }
    var upperClass=_className.toUpperCase();
    if(element.className){
        var classes=element.className.split(' ');
        for(var i=0;i<classes.length;i++){
            if(classes[i].toUpperCase()==upperClass){
                return true;
            }
        }
    }
    return false;
}
function isPanelExpanded(panel){
    return hasClass(panel,'expanded');
}
function expandPanel(panel){
    if(!isPanelExpanded(panel)){
        each(panel.parentNode.childNodes, function(item){
            if(panel!=item){
                collapsePanel(item);
            }
        });

        addClass(panel,'expanded');
        fireInlineEvent(panel,'expanded');
    }
}
function each(array,func){
    for(var i=0;i<array.length;i++)func(array[i]);
}
function addClass(element,_class){
    if(!hasClass(element,_class)){
        element.className+=element.className?(" "+_class):_class;
    }
}
function removeClass(element,_class){
    var upperClass=_class.toUpperCase();
    var remainingClasses=[];
    if(element.className){
        var classes=element.className.split(' ');
        for(var i=0;i<classes.length;i++){
            if(classes[i].toUpperCase()!=upperClass){
                remainingClasses[remainingClasses.length]=classes[i];
            }
        }
        element.className=remainingClasses.join(' ');
    }
}


  function leave_contributor(book_id)
  {
    if (confirm('您确定退出合作编缉？')==true)
    {
      $('<input type="hidden" name="book_id" value="'+book_id+'" />').appendTo('#bookViewForm');
      document.getElementById('bookViewForm').action = '/userLogin/leave_contributor';
      document.getElementById('bookViewForm').submit();
    }
    else
    {
      return;
    }
  }