[Dovecot] SOS

Hi,When i run "service dovecot start",I receive following line: Starting IMAP daemon (dovecot): Fatal: Can't use SSL key file /usr/share/ssl/private/dovecot.pem: No such file or directory
[FAILED]

Please guide me until i can make a key file.... Yours,Mohsen.

===== ---------DIGITAL SIGNATURE------------------- ///Mohsen Pahlevanzadeh//////// Network administrator & programmer
My work phone is : +98216054096-7
My home phone is: +98213810146
My emails is
m_pahlevanzadeh@yahoo.com
My website is: http://webnegar.net

Do you Yahoo!? Yahoo! Finance: Get your refund fast by filing online. http://taxes.yahoo.com/filing.html