multiple sub domain with multiple ssl certificate { SSL and apache }

I have a dedicated server which is pointed to the domain
www.domain1.com. I bought ssl sertificates for my domain x1.domain1.com which cost $10
so I bought ssl certificates for all sub domains, since wildcard certificate is too costly.

When i restart apache, the x1.domain1.com is getting set to the ssl certificate
on x2.domain1.com it shows an "untrusted warning" that this certificate is valid for some other domain. I checked the certificate itself, and it shows a domain of x1.domain1.com,
that is the certificicate of x1.domain1.com

How can I get multiple SSL vhosts set up?

My config file is

        ServerAdmin admin1@server1.com
        DocumentRoot /var/htm2/
        ServerName x1.domain1.com
        SSLEngine on
        SSLCertificateFile /usr/server.crt
        SSLCertificateKeyFile /usr/server.key 




 
        ServerAdmin admin2@server1.com
        DocumentRoot /var/htm/
        ServerName x2.domain1.com
        SSLEngine on
        SSLCertificateFile /usr/l/server.crt
        SSLCertificateKeyFile /usr/l/server.key  

the problem is i am having a single dedicated ip : 141.XX.XX.X but when i go to https://x1.domain1.com in chrome or firefox latest , the certificate works , but when i go to https://x2.domain1.com . it shows a certificate untrustness , and says conform trust of certificate as this certificate is for another domain , i viewed the certificate and saw it as certificate of x1.domain1.com

i want both of the sites to be browsed like

https:\\x1.domain1.com
https:\\x2.domain1.com   

with out any port or any thing ... what settings should i alter in the above config to attain this , what is the trouble which cause x2.domain1.com to show certificate of x1..domain and also how can i redirect

http:\x1.domain1.com to https:\x1.domain1.com with out using htaccess , if by htaccess then how ?

also how to redirect