question about cleaning up XHTML file

Hi, when i use tidy to clean up XHTML file, i got this error message:

"The table summary attribute should be used to describe
the table structure. It is very helpful for people using
non-visual browsers. The scope and headers attributes for
table cells are useful for specifying which headers apply
to each table cell, enabling non-visual browsers to provide
a meaningful context for each cell.

You are recommended to use CSS to specify the font and
properties such as its size and color. This will reduce
the size of HTML files and make them easier maintain
compared with using <FONT> elements."

I guess this error is from the format such as :

"<table border=1 cellspacing=0 cellpadding=0 style='margin-left:41.75pt;
 border-collapse:collapse;border:none;mso-border-bottom-alt:solid windowtext
.75pt;
 mso-padding-alt:0in 0in 0in 0in'>"

"<p class=MessageHeaderFirst style='margin-left:0in;text-indent:0in'><span
  class=MessageHeaderLabel><font size=1 face="Arial Black"><span
  style='font-size:9.0pt;mso-bidi-font-size:10.0pt;font-family:"Arial
Black";
  letter-spacing:-1.25pt'>T</span></font></span><span
class=MessageHeaderLabel><font
  size=1 face="Arial Black"><span style='font-size:9.0pt;mso-bidi-font-size:
  10.0pt;font-family:"Arial Black"'>o:</span></font></span></p>".

But i don't understand what exactly the error message is trying to tell me
and how to go around this.
Thanks so much for your help in advance.

Best regards,

Liwen

Received on Thursday, 21 September 2000 11:34:55 UTC