js获取fck文本编辑器内的内容，不包括html标签在内

//取fck内容的长度
function GetLength(str) {
var oEditor = FCKeditorAPI.GetInstance(str);
var checkContent = oEditor.EditorDocument;
var contentLength;
if (document.all) {
contentLength = trim(checkContent.body.innerText).length;
}
else {
var r = checkContent.createRange();
r.selectNodeContents(checkContent.body);
contentLength = trim(r).length;
}
return contentLength
}