how about
<table style=width:100%>
<tr>
<td style=text-align:center>
.... your table ....
</td>
</tr></table>

ask your question properly will be very helpful.
if you mean 3 conditions, then just use AND/OR to link up those conditions.

i think it will be more useful if you can make a through description of the error that you are getting

do you mean an ebook to prepare for certification or simply a guide on how to use mysql?

have u tried existing class like phpmailer? it's quite an extensive class and very useful

i think u can easily google for things like this. plenty of options out there.

I use mainly zend studio and vi if I am on linux and lazy to launch up zend.

won't it be too dangerous to allow commands to be executed that way? what if someone pass it delete command?