JS验证FCK内容是否为空

function CheckPost(){
try{
   if (GetMessageLength()==0){
         alert("内容不能为空!")
         return false
   }
  }
  catch(e){
    if (Trim(document.forms[0].Message.value)=="") {
         alert("内容不能为空!")
         try{document.forms[0].Message.focus()}catch(e){}
         return false
    }
  }
}

function GetMessageLength()
{
    var oEditor = FCKeditorAPI.GetInstance('Message') ;
    var oDOM = oEditor.EditorDocument ;
    var iLength ;

    if ( document.all )        // If Internet Explorer.
    {
        iLength = oDOM.body.innerText.length ;
    }
    else                    // If Gecko.
    {
        var r = oDOM.createRange() ;
        r.selectNodeContents( oDOM.body ) ;
        iLength = r.toString().length ;
    }
//    oEditor.InsertHtml('')
return iLength
}