Retrieving Rich Text Box value using JavaScript in SharePoint

Few days back I was working on one requirement to customize SharePoint list form(newform.aspx) using SharePoint designer 2007.

And I was unable to retrieve value from Rich Text box field "Analysis" in JavaScript.

I solved my issue using below JavaScript

<script type="text/javascript">

 var varAnalysis = getTagFromIdentifierAndTitle("textarea","TextField","Analysis*");
 var varAnalysisTextBoxID = RTE_GetEditorDocument(varAnalysis.id);
 var varAnalysisText = varAnalysisTextBoxID.body.innerText;

function getTagFromIdentifierAndTitle(tagName, identifier, title)
{
 var len = identifier.length;
 var tags = document.getElementsByTagName(tagName);
 for (var i=0; i < tags.length; i++)
 {
  var tempString = tags[i].id;
  if (tags[i].title == title && (identifier == "" || tempString.indexOf(identifier) == tempString.length - len))
  {
   return tags[i];
  }
 }
 return null;
}
</script>

This code solved my problem.