private string ExtractCenterContent(string htmlContent)
{
string centerContent = string.Empty;
string beginStr = "<!--BEGIN CENTER CONTENT-->";
string endStr = "<!--END CENTER CONTENT-->";
int startLocation = htmlContent.IndexOf(beginStr);
int endLocation = htmlContent.IndexOf(endStr);
if (startLocation == -1 || endLocation == -1) return string.Empty;
centerContent = htmlContent.Substring(startLocation + beginStr.Length, endLocation - (startLocation + beginStr.Length));
return centerContent;
}