PHP trim error on my simple captcha code

PHP trim error on my simple captcha code

When I try to implement a simple captcha in our website, I added the
following code in the page using the following code:
if( strlen($name) <3 or strlen($name) > 25){
$msg=$msg."Your Name should be more than 2 and less than 25 char
length<BR>";
$status= "NOTOK";}
if( strlen($dtl) <5 ){
$msg=$msg."Your comment should be more than 5 char length<BR>";
$status= "NOTOK";}
if( trim($verify)!='9') {
$msg=$msg."Your answer is not correct<BR>";
$status= "NOTOK";}
this code is working except these line
else if( trim($verify)!='9') {
$msg=$msg."Your answer is not correct<BR>";
$status= "NOTOK";}
but the same time this code working another server