connect web to mssql 2008 R2

[hcxd3333]

Warning: mssql_connect() [function.mssql-connect]: Unable to connect to server: 127.0.0.1 in D:\xampp\htdocs\Includes\SQL.php on line 18
Can't Connect To MSSQL Server!

Database have, config.php config 100%
have can i fix this?
sorry for bad eng

Fatal error: Call to undefined function mssql_connect() in C:\xampp\htdocs\config.php on line 12

[MentaL]

[KarLi]

it says clearly that it doesnt connects to MSSQL Server , so u gotta run ODBC .reg and change on config.inc the connection from "MSSQL to ODBC" and try out.