change script links using .htaccess

Hello,

I'm working on script, and want to set links to be as following:

www.mysite.com/sign-up.php
to
www.mysite.com/sign-up

I found this code and works for me.

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^(.+)$ $1.php [L,QSA] 

Code (markup):

BUT if I add a slash at the end of link, ex: www.mysite.com/sign-up/

it shows me this error

Internal Server Error
 
The server encountered an internal error or misconfiguration and was unable to complete your request.
 
Please contact the server administrator at admin@example.com to inform them of the time this error occurred, and the actions you performed just before this error.
 
More information about this error may be available in the server error log.

Code (markup):

Q2- if the user try to access any php extension, I want him to redirect to same link without extension

EX: www.mysite.com/sign-up.php
to
www.mysite.com/sign-up
Thank you

 

Replace last line with
RewriteRule ^(.*?)/?$ /$1.php [L]

 

I replaced so my .htaccess looks like

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^(.*?)/?$ /$1.php [L]

Code (markup):

but now all links doesn't work

shows me file not found

 

any one can help please?

 

if you add

RewriteRule ^(.*)/$ $1 [R=301,L]

Code (markup):

It should remove all trailing slashes

 

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f
RewriteRule ^(.+)$ $1.php [L,QSA]
 
RewriteRule ^(.*)/$ $1 [R=301,L]

Code (markup):

thanks but same problem