I've started making a shoutbox and wanted to get alternating backgrounds but it doesn't seem to work :S
This is my code:

<?php

$iplogging = 1;
$ipfile = "ips.txt";
$today = date("D M j G:i:s T Y");
		$ipl = fopen("$ipfile", "a");

		fwrite($ipl, "
Name: $name
Date: $today
Ip: $REMOTE_ADDR
Browser: $HTTP_USER_AGENT" 
);

$datfile = "shout.html";
$MAX_LENGTH = 3500;
$NUM_COMMENTS = 1000;


if (!$name)
{ $name = "Gast"; }
else $name .= "";

$c = preg_replace("/</","&lt;",$c);
$c = preg_replace("/>/","&gt;",$c); 
$c = str_replace(":)","<img src='smilies/smile.gif'>",$c);
$c = str_replace(":smiley:","<img src='smilies/smile-2.gif'>",$c);
$c = str_replace(":s","<img src='smilies/wacko.gif'>",$c);
$c = str_replace(":unsure:","<img src='smilies/unsure.gif'>",$c);
$c = str_replace(":p","<img src='smilies/toung.gif'>",$c);
$c = str_replace("|-)","<img src='smilies/suspicious.gif'>",$c);
$c = str_replace(";)","<img src='smilies/wink.gif'>",$c);
$c = str_replace(":worried:","<img src='smilies/worried.gif'>",$c);
$c = str_replace("O_o","<img src='smilies/weird.gif'>",$c);
$c = str_replace(":(","<img src='smilies/sad.gif'>",$c);
$c = str_replace(":yuck:","<img src='smilies/sick.gif'>",$c);
$c = str_replace(":(","<img src='smilies/sad.gif'>",$c);
$c = str_replace(":triest:","<img src='smilies/sad-2.gif'>",$c);
$c = str_replace("8)","<img src='smilies/rolleyes.gif'>",$c);
$c = str_replace("x)","<img src='smilies/push.gif'>",$c);
$c = str_replace(":|","<img src='smilies/oh.gif'>",$c);
$c = str_replace(":o","<img src='smilies/amazed.gif'>",$c);
$c = str_replace(":nuts:","<img src='smilies/nuts.gif'>",$c);
$c = str_replace(":noworry:","<img src='smilies/noworry.gif'>",$c);
$c = str_replace(":notrust:","<img src='smilies/notrust.gif'>",$c);
$c = str_replace(":@","<img src='smilies/mad.gif'>",$c);
$c = str_replace(":lol:","<img src='smilies/laugh.gif'>",$c);
$c = str_replace(":?:","<img src='smilies/huh.gif'>",$c);
$c = str_replace(":blozen:","<img src='smilies/embarrest.gif'>",$c);
$c = str_replace(":blijter:","<img src='smilies/crying.gif'>",$c);
$c = str_replace("(h)","<img src='smilies/cool.gif'>",$c);
$c = str_replace(":cheesy:","<img src='smilies/cheesy.gif'>",$c);
$c = str_replace(":D","<img src='smilies/bigsmile.gif'>",$c);
$comfile = file($datfile);
if ($c != "") {
if (strlen($c) < $MAX_LENGTH) {
$fd = fopen ($datfile, "w");
$c = stripslashes($c);


  if(($i%2)==0)
  {
    $bgcolor='#333333';
  }
  else
  {
    $bgcolor='#666666';
  }  
  fwrite ($fd, 
 "<tr bgcolor=$bgcolor align=\"left\">
<td><b><font color=\"#FF3300\">$name</font></b><font size =-2>($REMOTE_ADDR)</font><font color=\"FF3300\">:</font> $c</td>
   </tr>\n");


for ($i = 0; $i < $NUM_COMMENTS; $i++) {
fwrite ($fd, $comfile[$i]);
}
}
fclose($fd);
}
Header("Location: $HTTP_REFERER");



?>

hope someone can correct my mistake

Do you mean for each cell of a table? Sorry i couldn't be bothered to look through the code

This is how i combat the problem.

First off i have a loop dynamically creating each row (or <TR>), adding in the information needed.

Then, before the loop begins, claim a variable $x (or watever) and set that to '1'.

Here's the tricky bit, name the class of your <TR> or each <TD> (class as in CSS) as <TR CLASS=\"ColourBackground" . $CSSNo . "\">
This will mean that we need an if statement in the loop to control what number (1 or 2) is going to be contained in $CSSNo depending on the incrementing $x variable.

Hope you're following this! So, the if statement we need, within the loop is if($x%2): $CSSNo = "1"; else: $CSSNo = "2"; endif;

This checks to see if $x is an odd or even number.

Finally, when all operations within the loop are done, as $x++; so it increments the $x variable after every loop.

So you need 2 CSS classes, one named ColourBackground1 and ColourBackground2 and add the various crudentials in that you need

Hope that's sorta clear, im in a hurry